This issue, 75/1 is mostly dedicated to the environmental impact of landslides, which, due to current climate change, are becoming more and more pronounced around the world and in the Republic of Croatia. The six papers (BOSTJANČIĆ et al., 2022, Fig. 1 poly gon 1; FILIPOVIĆ et al., 2022, Fig. 1 polygon 2; FRANGEN et al., 2022, Fig. 1 polygon 3; GULAM et al., 2022, Fig. 1 polygon 4; PODOLSZKI et al., 2022, Fig. 1 polygon 5; POLLAK et al., 2022, Fig. 1 polygon 6) focusing on landslides are the result of the work of a large team of people from the Croatian Geological Sur vey, carried out within the framework of the safEarth project, cofinanced by the ERDF and IPA II funds of the European Union. As a part of the Interreg IPA – Cross-border Cooperation Programme Croatia – Bosnia and Herzegovina – Montenegro 2014-2020, the safEarth project was based on cross-border coop eration of four partner institutions, namely the Croatian Geological Survey (lead partner), Geological Survey of Montenegro, Faculty of Mining, Geology and Civil Engineering of the Univer sity of Tuzla and the Development Agency Žepče d.o.o. The main project activities were focused on landslide susceptibility maps (LSM) as one of the most important data sets in spatial planning The use of high-resolution LiDAR scanning in the research of small landslides based on Croatian examples
本期75/1主要讨论山体滑坡对环境的影响，由于目前的气候变化，这种影响在世界各地和克罗地亚共和国正变得越来越明显。六篇论文(BOSTJANČIĆ et al.， 2022，图1多边形1;FILIPOVIĆ等人，2022，图1多边形2;FRANGEN et al.， 2022，图1多边形3;GULAM等人，2022，图1多边形4;PODOLSZKI等人，2022，图1多边形5;POLLAK等人，2022年，图1多边形6)专注于滑坡，这是克罗地亚地质调查局的一个大型团队的工作成果，该团队在safEarth项目框架内进行，由ERDF和欧盟IPA II基金共同资助。作为Interreg IPA -克罗地亚-波斯尼亚和黑塞哥维那-黑山2014-2020年跨境合作方案的一部分，安全地球项目以四个伙伴机构的跨境合作为基础，即克罗地亚地质调查局(牵头伙伴)、黑山地质调查局、矿业学院、图兹拉大学地质与土木工程与发展机构Žepče d.o.o.主要项目活动集中在滑坡易感性图(LSM)上，这是空间规划中最重要的数据集之一，在基于克罗地亚实例的小型滑坡研究中使用高分辨率激光雷达扫描
{"title":"Editorial: The use of high-resolution LiDAR scanning in the research of small landslides based on Croatian examples","authors":"K. Mandžić, Vlatko Gulam, L. Galović","doi":"10.4154/gc.2022.13","DOIUrl":"https://doi.org/10.4154/gc.2022.13","url":null,"abstract":"This issue, 75/1 is mostly dedicated to the environmental impact of landslides, which, due to current climate change, are becoming more and more pronounced around the world and in the Republic of Croatia. The six papers (BOSTJANČIĆ et al., 2022, Fig. 1 poly gon 1; FILIPOVIĆ et al., 2022, Fig. 1 polygon 2; FRANGEN et al., 2022, Fig. 1 polygon 3; GULAM et al., 2022, Fig. 1 polygon 4; PODOLSZKI et al., 2022, Fig. 1 polygon 5; POLLAK et al., 2022, Fig. 1 polygon 6) focusing on landslides are the result of the work of a large team of people from the Croatian Geological Sur vey, carried out within the framework of the safEarth project, cofinanced by the ERDF and IPA II funds of the European Union. As a part of the Interreg IPA – Cross-border Cooperation Programme Croatia – Bosnia and Herzegovina – Montenegro 2014-2020, the safEarth project was based on cross-border coop eration of four partner institutions, namely the Croatian Geological Survey (lead partner), Geological Survey of Montenegro, Faculty of Mining, Geology and Civil Engineering of the Univer sity of Tuzla and the Development Agency Žepče d.o.o. The main project activities were focused on landslide susceptibility maps (LSM) as one of the most important data sets in spatial planning The use of high-resolution LiDAR scanning in the research of small landslides based on Croatian examples","PeriodicalId":55108,"journal":{"name":"Geologia Croatica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48133931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Iris Bostjančić, Radovan Avanić, Tihomir Frangen, M. Pavić
A preliminary analysis of landslide spatial distribution and their geometric characteristics is presented for the area of Slavonski Brod, located in the northeastern part of Croatia and belonging to the Pannonian Basin System. A landslide inventory for the study area of 55.1 km2 is accomplished for the first time, based on the visual interpretation of a high resolution LiDAR digital terrain model. In total, 854 landslide polygons are delineated, corresponding to an average density of 15.5 landslides per square kilometre. The average landslide area is 839 m2, and most of the landslides can be classified as small landslides (76 %). The spatial relationship between landslides and geological units is analysed and expressed as a landslide index. The Late Pannonian sands with silts and gravel interlayers and Pliocene clay, sands, gravels, and coal are determined as the units that are most susceptible to landslide processes. The majority of landslides (85 %) are concentrated within these two units, for which a detailed analysis is performed, determining the morphometric parameters (slope and relief) and drainage network. The parameters’ classes that create favourable preconditions to slope instabilities are defined, based on the landslide density within individual classes. Besides, the geometric characteristics of landslides (size and shape) within these two units are compared. The results serve as the basis for further investigations. They help to foresee the area of future landslides through landslide susceptibility maps, and offer a better understanding of the influence of fluvial-denudation and slope processes on recent landscape evolution and form.
{"title":"Spatial distribution and geometric characteristics of landslides with special reference to geological units in the area of Slavonski Brod, Croatia","authors":"Iris Bostjančić, Radovan Avanić, Tihomir Frangen, M. Pavić","doi":"10.4154/gc.2022.03","DOIUrl":"https://doi.org/10.4154/gc.2022.03","url":null,"abstract":"A preliminary analysis of landslide spatial distribution and their geometric characteristics is presented for the area of Slavonski Brod, located in the northeastern part of Croatia and belonging to the Pannonian Basin System. A landslide inventory for the study area of 55.1 km2 is accomplished for the first time, based on the visual interpretation of a high resolution LiDAR digital terrain model. In total, 854 landslide polygons are delineated, corresponding to an average density of 15.5 landslides per square kilometre. The average landslide area is 839 m2, and most of the landslides can be classified as small landslides (76 %). The spatial relationship between landslides and geological units is analysed and expressed as a landslide index. The Late Pannonian sands with silts and gravel interlayers and Pliocene clay, sands, gravels, and coal are determined as the units that are most susceptible to landslide processes. The majority of landslides (85 %) are concentrated within these two units, for which a detailed analysis is performed, determining the morphometric parameters (slope and relief) and drainage network. The parameters’ classes that create favourable preconditions to slope instabilities are defined, based on the landslide density within individual classes. Besides, the geometric characteristics of landslides (size and shape) within these two units are compared. The results serve as the basis for further investigations. They help to foresee the area of future landslides through landslide susceptibility maps, and offer a better understanding of the influence of fluvial-denudation and slope processes on recent landscape evolution and form.","PeriodicalId":55108,"journal":{"name":"Geologia Croatica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41624508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a preliminary analysis of the landslide inventory is presented for the wider area of the municipalities of Glina and Dvor, within Sisak-Moslavina County in Croatia, where LiDAR scanning for 45.85 km2 was conducted. Landslide polygons were outlined based on the visual interpretation of HRDEM derivates. In total, 477 landslides were contoured with an average landslide density of 9.85 per km2. Most of the landslides are characterised as moderate, shallow, and not recent. The spatial relationship between landslides and geological units is expressed with the landslide index. Subsequently, the geological units were grouped into four engineering geological units representing different susceptibilities to landslides. The geological units most prone to landslides are the Eocene, Oligocene, Palaeocene and Jurassic sandstones. Even though all geological units were analysed here, the majority of landslides are within sandstones. A particular emphasis was on landslide occurrence in metamorphic and igneous rocks of the ophiolite sequence, a distinctive characteristic of the research area where less susceptibility to landslide processes was observed. Moreover, to further distinguish the differences between the units in the area a morphometric characteristic (relief) and drainage network was also analysed. The purpose of this analysis was to additionally confirm the landslide susceptibility assessment and the division of geological units into engineering geological units, which again implied the different behaviours between landslides in igneous and metamorphic rocks compared to sandstones. Because the research area is poorly studied regarding landslide susceptibility, relief, and drainage networks, these findings will be a step forward in recognising the relationship between them and creating a base for the development of a landslide susceptibility map for this area.
{"title":"A case study in the research polygon in Glina and Dvor municipality, Croatia–landslide susceptibility assessment of geological units","authors":"M. Filipović, Ivan Mišur, Vlatko Gulam, M. Horvat","doi":"10.4154/gc.2022.04","DOIUrl":"https://doi.org/10.4154/gc.2022.04","url":null,"abstract":"In this paper, a preliminary analysis of the landslide inventory is presented for the wider area of the municipalities of Glina and Dvor, within Sisak-Moslavina County in Croatia, where LiDAR scanning for 45.85 km2 was conducted. Landslide polygons were outlined based on the visual interpretation of HRDEM derivates. In total, 477 landslides were contoured with an average landslide density of 9.85 per km2. Most of the landslides are characterised as moderate, shallow, and not recent. The spatial relationship between landslides and geological units is expressed with the landslide index. Subsequently, the geological units were grouped into four engineering geological units representing different susceptibilities to landslides. The geological units most prone to landslides are the Eocene, Oligocene, Palaeocene and Jurassic sandstones. Even though all geological units were analysed here, the majority of landslides are within sandstones. A particular emphasis was on landslide occurrence in metamorphic and igneous rocks of the ophiolite sequence, a distinctive characteristic of the research area where less susceptibility to landslide processes was observed. Moreover, to further distinguish the differences between the units in the area a morphometric characteristic (relief) and drainage network was also analysed. The purpose of this analysis was to additionally confirm the landslide susceptibility assessment and the division of geological units into engineering geological units, which again implied the different behaviours between landslides in igneous and metamorphic rocks compared to sandstones. Because the research area is poorly studied regarding landslide susceptibility, relief, and drainage networks, these findings will be a step forward in recognising the relationship between them and creating a base for the development of a landslide susceptibility map for this area.","PeriodicalId":55108,"journal":{"name":"Geologia Croatica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47605823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zoran Kovač, Stanko Ružičić, V. Rubinić, Zoran Nakić, Marcel Sertić
Contamination of soils with potentially toxic metals (PTMs) is an environmental problem. In this study, sorption of cadmium (Cd), zinc (Zn) and copper (Cu) in four soil profiles (two Fluvisols, one Gleysol, and one Cambisol), representing the dominant soils of the Zagreb aquifer system, were studied using a multi element laboratory batch test. Mathematical expressions were applied to establish the relationship between the concentration of the adsorbent in the liquid phase and the solid phaSe at equilibrium and in laboratory conditions. The study revealed that the investigated soils have a higher capacity to sorb Cu than Zn and Cd. The most significant physicochemical characteristics of soils, influencing sorption, are pH, carbonate content (minerals) and organic matter. Although all PTMs in all analyzed soils had a similar sorption capacity, the variation of sorption was higher in the siltic soils (Fluvisols) compared with the texturally finer (loamic) Gleysol and Cambisol soils, as well as in the subsoil horizons compared with the topsoils. Results indicate that sorption of PTMs is more influenced by physicochemical characteristics at different soil depths than by soil type, which is confirmed with a higher affinity for Zn and Cd bonding in the topsoil horizons. Also, it has been shown that Cd may pose more of a threat to soils and groundwater due to its toxicity and relatively high mobility in comparison with Zn and Cu.
{"title":"Sorption of cadmium, zinc and copper in dominant soils of the Zagreb aquifer system, Croatia","authors":"Zoran Kovač, Stanko Ružičić, V. Rubinić, Zoran Nakić, Marcel Sertić","doi":"10.4154/gc.2022.05","DOIUrl":"https://doi.org/10.4154/gc.2022.05","url":null,"abstract":"Contamination of soils with potentially toxic metals (PTMs) is an environmental problem. In this study, sorption of cadmium (Cd), zinc (Zn) and copper (Cu) in four soil profiles (two Fluvisols, one Gleysol, and one Cambisol), representing the dominant soils of the Zagreb aquifer system, were studied using a multi element laboratory batch test. Mathematical expressions were applied to establish the relationship between the concentration of the adsorbent in the liquid phase and the solid phaSe at equilibrium and in laboratory conditions. The study revealed that the investigated soils have a higher capacity to sorb Cu than Zn and Cd. The most significant physicochemical characteristics of soils, influencing sorption, are pH, carbonate content (minerals) and organic matter. Although all PTMs in all analyzed soils had a similar sorption capacity, the variation of sorption was higher in the siltic soils (Fluvisols) compared with the texturally finer (loamic) Gleysol and Cambisol soils, as well as in the subsoil horizons compared with the topsoils. Results indicate that sorption of PTMs is more influenced by physicochemical characteristics at different soil depths than by soil type, which is confirmed with a higher affinity for Zn and Cd bonding in the topsoil horizons. Also, it has been shown that Cd may pose more of a threat to soils and groundwater due to its toxicity and relatively high mobility in comparison with Zn and Cu.","PeriodicalId":55108,"journal":{"name":"Geologia Croatica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42802546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Sadeghi, N. Nezafati, Saeid Hakimi-Asiabar, A. Ganji
The Duna Pb-Ba-(Ag) mine is located ca. 155 km north of Tehran in the central Alborz structural zone, northern Iran. The ore mineralization occurs as stratabound, epigenetic, E-W and WSWENE trending veins and veinlets in fracture-controlled as well as massive and open-space filling textures within a Permian dolomitic limestone host rock. Field observations as well as mineralogical and petrographic studies show dolomitization, silicification and possibly haematisation in the host rock. In the mineralization zone, galena and barite are the main minerals, followed by pyrite, quartz, chalcopyrite, tetrahedrite, sphalerite, calcite and supergene minerals such as covellite, malachite, azurite, cerussite, anglesite, and Fe-oxides. The chemical analyses of the highgrade ore samples show an average grade of 18.66 wt. % for Pb, 19.99 wt. % for Ba, and 120 ppm for Ag together with substantial quantities of Zn (0.15 wt. %), As (690 ppm), Cu (0.86 wt. %), Sb (0.25 wt. %), and Sr (0.56 wt. %). The amount of silver in some samples from the tunnel and discordant layers is up to 7030 ppm. The positive Eu/Eu⃰ ratio and the weak negative Ce/Ce⃰ anomaly in the ore samples were most likely inherited from magmatic water. The presence of minerals such as pyrite and chalcopyrite together with the co-precipitation of sphalerite and chalcopyrite suggest a high-temperature for mineralizing fluids. The homogenization temperatures of fluid inclusions from barite in concordant layers span between 135 and 165 ºC with salinities between 18.54 and 23.65 wt. % NaCl equivalent, while the homogenization temperatures of fluid inclusions from barite of discordant layers span between 113 and 285 ºC with salinities between 7.34 and 23.65 wt. % NaCl equivalent. The structural, geological, geochemical, and mineralogical studies together with the paragenesis of the ore minerals and fluid inclusion data allow consideration of the Duna Pb-Ba-(Ag) mine as a two stage mineralization scenario; 1st stage /older/MVT-type (Early Cimmerian tectonic phase), and the second stage/younger/Irish-type (Laramide orogenic movements). The structural data, high temperature of the fluid inclusions, positive Eu/Eu⃰ ratio and high silver content, especially in the discordant layers, indicate the involvement of a magmatic water mixed with meteoric and connate fluids comparable to the Irishtype mineralization in the second stage, which formed along brecciated zones of the thrust faults. The second stage of mineralization was most likely influenced by the Akapol granitoid intrusive mass, which overprinted the 1st stage/older/MVT-type.
{"title":"Geological, geochemical and fluid inclusion investigations on the Duna Pb-Ba-(Ag) deposit, Central Alborz, North Central Iran","authors":"A. Sadeghi, N. Nezafati, Saeid Hakimi-Asiabar, A. Ganji","doi":"10.4154/gc.2022.08","DOIUrl":"https://doi.org/10.4154/gc.2022.08","url":null,"abstract":"The Duna Pb-Ba-(Ag) mine is located ca. 155 km north of Tehran in the central Alborz structural zone, northern Iran. The ore mineralization occurs as stratabound, epigenetic, E-W and WSWENE trending veins and veinlets in fracture-controlled as well as massive and open-space filling textures within a Permian dolomitic limestone host rock. Field observations as well as mineralogical and petrographic studies show dolomitization, silicification and possibly haematisation in the host rock. In the mineralization zone, galena and barite are the main minerals, followed by pyrite, quartz, chalcopyrite, tetrahedrite, sphalerite, calcite and supergene minerals such as covellite, malachite, azurite, cerussite, anglesite, and Fe-oxides. The chemical analyses of the highgrade ore samples show an average grade of 18.66 wt. % for Pb, 19.99 wt. % for Ba, and 120 ppm for Ag together with substantial quantities of Zn (0.15 wt. %), As (690 ppm), Cu (0.86 wt. %), Sb (0.25 wt. %), and Sr (0.56 wt. %). The amount of silver in some samples from the tunnel and discordant layers is up to 7030 ppm. The positive Eu/Eu⃰ ratio and the weak negative Ce/Ce⃰ anomaly in the ore samples were most likely inherited from magmatic water. The presence of minerals such as pyrite and chalcopyrite together with the co-precipitation of sphalerite and chalcopyrite suggest a high-temperature for mineralizing fluids. The homogenization temperatures of fluid inclusions from barite in concordant layers span between 135 and 165 ºC with salinities between 18.54 and 23.65 wt. % NaCl equivalent, while the homogenization temperatures of fluid inclusions from barite of discordant layers span between 113 and 285 ºC with salinities between 7.34 and 23.65 wt. % NaCl equivalent. The structural, geological, geochemical, and mineralogical studies together with the paragenesis of the ore minerals and fluid inclusion data allow consideration of the Duna Pb-Ba-(Ag) mine as a two stage mineralization scenario; 1st stage /older/MVT-type (Early Cimmerian tectonic phase), and the second stage/younger/Irish-type (Laramide orogenic movements). The structural data, high temperature of the fluid inclusions, positive Eu/Eu⃰ ratio and high silver content, especially in the discordant layers, indicate the involvement of a magmatic water mixed with meteoric and connate fluids comparable to the Irishtype mineralization in the second stage, which formed along brecciated zones of the thrust faults. The second stage of mineralization was most likely influenced by the Akapol granitoid intrusive mass, which overprinted the 1st stage/older/MVT-type.","PeriodicalId":55108,"journal":{"name":"Geologia Croatica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43262625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study was undertaken to quantify and evaluate the density and porosity characteristics of a Boda Claystone Formation (BCF) core sample using medical CT. Each voxel of the 3D CT volume was described with three variables: dry CT number, saturated CT number, and effective porosity. Disparity pore voxels were revealed using the genetic groups’ algorithm of data-mining techniques. The K-fold cross-validation algorithm has been applied to determine the number of the most stable cluster. The 3D spatial distributions of voxel-porosity by rock constituents, as well as the 3D distribution of porosity clusters by rock components, were found by Boolean function implementation. The terrigenous detrital fragments had the lowest porosity mean (0.16%) and highest coefficient variation value (1039.39%). While the Fine siltstone component had the highest porosity mean (3.39%) and lower coefficient of variation (134.99%). The difference in the variation of coefficient proportions is related to the outlier ratios in each rock component. Independently of both the rock types and the sedimentary structures, two clusters could be defined: one for the micro-porosity and one for the macro-porosity regimes. The former showed a continuous 3D spatial appearance, while the latter appeared in patches. These patches may also be connected, at least partly, to some local smectite aggregates. These clay minerals could lose their structured water content during vacuuming and swell when adsorbing water during sample saturation. In each rock type, the micro-porosity regime could be related to low-density rock fragments. The mean effective porosity of the micro-pore regime was about 0.02, which corresponds to the petrophysical core measurements. For the macro regimes, the average was 0.1.
{"title":"Evaluation Of 3D small-scale lithological heterogeneities and pore distribution of the Boda Claystone Formation using X-Ray Computed Tomography images (CT)","authors":"Saja Abutaha, J. Geiger, S. Gulyás","doi":"10.4154/gc.2021.17","DOIUrl":"https://doi.org/10.4154/gc.2021.17","url":null,"abstract":"This study was undertaken to quantify and evaluate the density and porosity characteristics of a Boda Claystone Formation (BCF) core sample using medical CT. Each voxel of the 3D CT volume was described with three variables: dry CT number, saturated CT number, and effective porosity. Disparity pore voxels were revealed using the genetic groups’ algorithm of data-mining techniques. The K-fold cross-validation algorithm has been applied to determine the number of the most stable cluster. The 3D spatial distributions of voxel-porosity by rock constituents, as well as the 3D distribution of porosity clusters by rock components, were found by Boolean function implementation. The terrigenous detrital fragments had the lowest porosity mean (0.16%) and highest coefficient variation value (1039.39%). While the Fine siltstone component had the highest porosity mean (3.39%) and lower coefficient of variation (134.99%). The difference in the variation of coefficient proportions is related to the outlier ratios in each rock component. Independently of both the rock types and the sedimentary structures, two clusters could be defined: one for the micro-porosity and one for the macro-porosity regimes. The former showed a continuous 3D spatial appearance, while the latter appeared in patches. These patches may also be connected, at least partly, to some local smectite aggregates. These clay minerals could lose their structured water content during vacuuming and swell when adsorbing water during sample saturation. In each rock type, the micro-porosity regime could be related to low-density rock fragments. The mean effective porosity of the micro-pore regime was about 0.02, which corresponds to the petrophysical core measurements. For the macro regimes, the average was 0.1.","PeriodicalId":55108,"journal":{"name":"Geologia Croatica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45258297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Surić, Robert Lončarić, Matea Kulišić, Lukrecija Sršen
Carbon dioxide (CO2) concentration (CDC) plays an important role in karst processes, governing both carbonate deposition and dissolution, affecting not only natural processes, but also human activities in caves adapted for tourism. Its variations due to various controlling parameters was observed from 2017 to 2021 in two Croatian show caves (Manita peć and Modrič) where we examined inter- and within-cave correlation of internal aerology regarding the sources, sinks and transport mechanism of CDC in a karst conduit setting. In both caves, the main sources of CO2 are: i) plant and microbial activity i.e. root respiration and organic matter decay within soil horizons and fractured epikarst, and ii) degassing from CO2-rich percolation water. The main sink of CO2 is dilution with outside air due to cave ventilation. Chimney-effect driven ventilation controlled by seasonal differences between surface and cave air temperatures shows winter (ToutTcave ) ventilation regime, which are modulated by the geometry of cave passages, the transmissivity of the overlying epikarst, and occasionally by the external winds, especially the gusty north-eastern bora wind. In these terms, the Modrič Cave appears to be more confined and less ventilated, with a substantial CDC difference between the left (550-7200 ppm) and right (1475- >10,000 ppm) passages. The Manita peć Cave is, in contrast, ventilated almost year-round, having 7 months of CDC equilibrated with the outside atmosphere and the highest summer CDC values of ~1410 ppm. In both caves, at the current level of tourist use, anthropogenic CO2 flux is not a matter of concern for cave conservation. In turn, in the innermost part of the right Modrič Cave passage visitors’ health might be compromised, but the tourists are allowed only in the left passage. Speleothem growth rate, recognized as a useful palaeoenvironmental proxy for speleothem-based palaeoclimate studies, strongly depends on CDC variations, so the high CDCs recorded in the Modrič Cave indicate the potential periods with no speleothem deposition due to the hampered degassing of CO2 from the dripping groundwater. The opposite effect i.e. enhanced ventilation (that supports calcite precipitation) during the windy glacials/stadials, as well as substantial vegetational changes must also be taken into consideration when interpreting environmental records from spelean calcite.
{"title":"Spatio-temporal variations of cave-air CO2 concentrations in two Croatian show caves: Natural vs. anthropogenic controls","authors":"M. Surić, Robert Lončarić, Matea Kulišić, Lukrecija Sršen","doi":"10.4154/gc.2021.21","DOIUrl":"https://doi.org/10.4154/gc.2021.21","url":null,"abstract":"Carbon dioxide (CO2) concentration (CDC) plays an important role in karst processes, governing both carbonate deposition and dissolution, affecting not only natural processes, but also human activities in caves adapted for tourism. Its variations due to various controlling parameters was observed from 2017 to 2021 in two Croatian show caves (Manita peć and Modrič) where we examined inter- and within-cave correlation of internal aerology regarding the sources, sinks and transport mechanism of CDC in a karst conduit setting. In both caves, the main sources of CO2 are: i) plant and microbial activity i.e. root respiration and organic matter decay within soil horizons and fractured epikarst, and ii) degassing from CO2-rich percolation water. The main sink of CO2 is dilution with outside air due to cave ventilation. Chimney-effect driven ventilation controlled by seasonal differences between surface and cave air temperatures shows winter (ToutTcave ) ventilation regime, which are modulated by the geometry of cave passages, the transmissivity of the overlying epikarst, and occasionally by the external winds, especially the gusty north-eastern bora wind. In these terms, the Modrič Cave appears to be more confined and less ventilated, with a substantial CDC difference between the left (550-7200 ppm) and right (1475- >10,000 ppm) passages. The Manita peć Cave is, in contrast, ventilated almost year-round, having 7 months of CDC equilibrated with the outside atmosphere and the highest summer CDC values of ~1410 ppm. In both caves, at the current level of tourist use, anthropogenic CO2 flux is not a matter of concern for cave conservation. In turn, in the innermost part of the right Modrič Cave passage visitors’ health might be compromised, but the tourists are allowed only in the left passage. Speleothem growth rate, recognized as a useful palaeoenvironmental proxy for speleothem-based palaeoclimate studies, strongly depends on CDC variations, so the high CDCs recorded in the Modrič Cave indicate the potential periods with no speleothem deposition due to the hampered degassing of CO2 from the dripping groundwater. The opposite effect i.e. enhanced ventilation (that supports calcite precipitation) during the windy glacials/stadials, as well as substantial vegetational changes must also be taken into consideration when interpreting environmental records from spelean calcite.","PeriodicalId":55108,"journal":{"name":"Geologia Croatica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48963273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Frane Marković, K. Kuiper, S. Ćorić, Valentina Hajek-Tadesse, Morana Hernitz Kučenjak, K. Bakrač, Đurđica Pezelj, M. Kovácic
In the North Croatian Basin which is located in the southwestern part of the Pannonian Basin System, Miocene tuff deposits have been observed at several localities in the area of Banovina, Medvednica Mt. and Slavonia. Here we present new 40Ar/39Ar age results obtained from volcanic glass from the Laz tuff (15.42 ± 0.15 Ma) intercalated with lacustrine freshwater/brackish deposits, the Jovac tuff (15.10 ± 0.06 Ma) intercalated with lacustrine freshwater deposits, the Čučerje tuff (14.81 ± 0.08 Ma) and the Nježić tuff (14.40 ± 0.03 Ma) both deposited in a marine environment. Fossil data (calcareous nannofossils/foraminifera) from the underlying and overlying beds of the tuffs from Čučerje and Nježić match the geochronological data i.e. NN5 zone and M6 zone were determined. Integration of biostratigraphic and geochronological data enable a better understanding of the NCB sedimentary evolution and constrain the Middle Miocene marine flooding event in the marginal areas of the western part of the NCB at ~15 Ma i.e. early/middle Badenian boundary. These results together with the existence of lower Badenian marine sediments in the Sava depression (in the southern part of NCB) suggest it is possible to conclude that during the early Badenian in the NCB, freshwater lacustrine and marine environments coexisted.
{"title":"Middle Miocene marine flooding: New 40Ar/39Ar age constraints with integrated biostratigraphy on tuffs from the North Croatian Basin","authors":"Frane Marković, K. Kuiper, S. Ćorić, Valentina Hajek-Tadesse, Morana Hernitz Kučenjak, K. Bakrač, Đurđica Pezelj, M. Kovácic","doi":"10.4154/gc.2021.18","DOIUrl":"https://doi.org/10.4154/gc.2021.18","url":null,"abstract":"In the North Croatian Basin which is located in the southwestern part of the Pannonian Basin System, Miocene tuff deposits have been observed at several localities in the area of Banovina, Medvednica Mt. and Slavonia. Here we present new 40Ar/39Ar age results obtained from volcanic glass from the Laz tuff (15.42 ± 0.15 Ma) intercalated with lacustrine freshwater/brackish deposits, the Jovac tuff (15.10 ± 0.06 Ma) intercalated with lacustrine freshwater deposits, the Čučerje tuff (14.81 ± 0.08 Ma) and the Nježić tuff (14.40 ± 0.03 Ma) both deposited in a marine environment. Fossil data (calcareous nannofossils/foraminifera) from the underlying and overlying beds of the tuffs from Čučerje and Nježić match the geochronological data i.e. NN5 zone and M6 zone were determined. Integration of biostratigraphic and geochronological data enable a better understanding of the NCB sedimentary evolution and constrain the Middle Miocene marine flooding event in the marginal areas of the western part of the NCB at ~15 Ma i.e. early/middle Badenian boundary. These results together with the existence of lower Badenian marine sediments in the Sava depression (in the southern part of NCB) suggest it is possible to conclude that during the early Badenian in the NCB, freshwater lacustrine and marine environments coexisted.","PeriodicalId":55108,"journal":{"name":"Geologia Croatica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42914735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eğerci village is located 16 km southwest of Yerköy (Yozgat) area which has a ferromanganese deposit that formed at the contact between basalt and limestone and shows that a banded stockwork structure occurs occasionally within the limestone. The mineralization consists of pyrolusite, goethite, and ramsdellite, together with a lesser quantity of magnetite. Gangue minerals are determined as calcite and quartz. REE data from the mineral samples demonstrate a range from 2.70 - 63.70 ppm and the average value is 28.00. These results permit a comparison to be made with mineralization in hydrothermal deposits. Moreover, mineral samples show a positive Eu anomaly 0.88-48.10 ppm (ave. 9.94 ppm). The Ce anomaly values vary between 0.02 and 0.88 ppm (ave. 0.58 ppm). It is possible that the mineralization may be affected by the mixing of seawater and hydrothermal fluids. The value of the positive Eu anomaly is evidence of modern oceanic hydrothermal manganese deposits. Insight of previous fluid inclusion, studies can be easily inferred that mineralization can occur at three different stages. The temperature of the first stage ranged from 338 oC to 428 oC and other stages vary from 269 oC - 317 oC and 143 oC - 236 oC, respectively. As a comparison, calculated salinity is higher in Type I fluid inclusions (1.9-14.7 wt.% NaCl equiv.) than Type II and III fluid inclusions (1.9-5.1 wt.%NaCl (equiv.) It is possible that the mineralization was formed by the mixing of magmatic and meteoric waters.
{"title":"Genesis of ferromanganese deposits from the Central Anatolian province, Yozgat-Aşağı Eğerci village, Turkey: Geochemical properties and fluid inclusions","authors":"Nur Öksüz, Sümeyra Kaya","doi":"10.4154/gc.2021.20","DOIUrl":"https://doi.org/10.4154/gc.2021.20","url":null,"abstract":"Eğerci village is located 16 km southwest of Yerköy (Yozgat) area which has a ferromanganese deposit that formed at the contact between basalt and limestone and shows that a banded stockwork structure occurs occasionally within the limestone. The mineralization consists of pyrolusite, goethite, and ramsdellite, together with a lesser quantity of magnetite. Gangue minerals are determined as calcite and quartz. REE data from the mineral samples demonstrate a range from 2.70 - 63.70 ppm and the average value is 28.00. These results permit a comparison to be made with mineralization in hydrothermal deposits. Moreover, mineral samples show a positive Eu anomaly 0.88-48.10 ppm (ave. 9.94 ppm). The Ce anomaly values vary between 0.02 and 0.88 ppm (ave. 0.58 ppm). It is possible that the mineralization may be affected by the mixing of seawater and hydrothermal fluids. The value of the positive Eu anomaly is evidence of modern oceanic hydrothermal manganese deposits. Insight of previous fluid inclusion, studies can be easily inferred that mineralization can occur at three different stages. The temperature of the first stage ranged from 338 oC to 428 oC and other stages vary from 269 oC - 317 oC and 143 oC - 236 oC, respectively. As a comparison, calculated salinity is higher in Type I fluid inclusions (1.9-14.7 wt.% NaCl equiv.) than Type II and III fluid inclusions (1.9-5.1 wt.%NaCl (equiv.) It is possible that the mineralization was formed by the mixing of magmatic and meteoric waters.","PeriodicalId":55108,"journal":{"name":"Geologia Croatica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42626107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Viviparus beds are sediments deposited in lacustrine and fluvial freshwater environments (Lake Slavonia) during the Pliocene and the earliest Pleistocene. A detailed field study and mineralogical, petrographic and chemical analyses were carried out to determine their composition and origin in the area of Vukomeričke Gorice, Central Croatia. Viviparus beds are characterized by the vertical and lateral exchange of mineralogically and chemically mature pelites and sands. Pelitic sediments consist mainly of detrital quartz, calcite, dolomite and feldspar grains, with smectite as the most common clay mineral. Quartz and the most resistant lithic fragments dominate the sandy detritus. The composition of the sediments indicates their origin from the recycled orogen, while their textural immaturity suggests a short transport distance. Most of the material was re-deposited from the underlying Upper Miocene sediments, originally of Alpine provenance. A lesser proportion originated from Palaeogene sediments, Triassic carbonate rocks, basic or acidic magmatic rocks and metamorphites. The Medvednica and Žumberak Mts. were the most important source areas, while a smaller proportion of the material could have come from the Moslavačka gora Mt. and Banovina region. The uniform composition of the Viviparus beds over the entire vertical distribution of the sediments clearly indicates that the source areas did not change during their deposition. A significant change from the texturally and compositionally mature Upper Miocene clastic detritus of alpine origin, to the texturally immature material of the Viviparus beds of local origin is a consequence of compression and inversion of the previously extensional basin resulting in the uplifting and erosion of the mountains within the SW part of the Pannonian Basin System.
{"title":"Mineral assemblage and provenance of the Pliocene Viviparus beds from the Area of Vukomeričke Gorice (Central Croatia)","authors":"Tomislav Kurečić, M. Kovácic, A. Grizelj","doi":"10.4154/gc.2021.16","DOIUrl":"https://doi.org/10.4154/gc.2021.16","url":null,"abstract":"Viviparus beds are sediments deposited in lacustrine and fluvial freshwater environments (Lake Slavonia) during the Pliocene and the earliest Pleistocene. A detailed field study and mineralogical, petrographic and chemical analyses were carried out to determine their composition and origin in the area of Vukomeričke Gorice, Central Croatia. Viviparus beds are characterized by the vertical and lateral exchange of mineralogically and chemically mature pelites and sands. Pelitic sediments consist mainly of detrital quartz, calcite, dolomite and feldspar grains, with smectite as the most common clay mineral. Quartz and the most resistant lithic fragments dominate the sandy detritus. The composition of the sediments indicates their origin from the recycled orogen, while their textural immaturity suggests a short transport distance. Most of the material was re-deposited from the underlying Upper Miocene sediments, originally of Alpine provenance. A lesser proportion originated from Palaeogene sediments, Triassic carbonate rocks, basic or acidic magmatic rocks and metamorphites. The Medvednica and Žumberak Mts. were the most important source areas, while a smaller proportion of the material could have come from the Moslavačka gora Mt. and Banovina region. The uniform composition of the Viviparus beds over the entire vertical distribution of the sediments clearly indicates that the source areas did not change during their deposition. A significant change from the texturally and compositionally mature Upper Miocene clastic detritus of alpine origin, to the texturally immature material of the Viviparus beds of local origin is a consequence of compression and inversion of the previously extensional basin resulting in the uplifting and erosion of the mountains within the SW part of the Pannonian Basin System.","PeriodicalId":55108,"journal":{"name":"Geologia Croatica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44377391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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