Three stratigraphical sections and several outcrops through the upper Silurian graptolite shales of the Muhurr area, Albania have been revised. Based on a new detailed re-examination and re-evaluation of graptolite collections and previously unpublished and published studies, a biozonal scheme with much new biostratigraphical data is established. The graptolite assemblages are dominated by Monograptidae: Neodiversograptus, Saetograptus, Bohemograptus, Colonograptus, Pseudomonoclimacis and Lobograptus which are associated with several Retiolitidae. A total of 37 graptolite species has been identified; selected important species are illustrated. The present study recognized and defined the following seven upper Silurian graptolite biozones: nilssoni and scanicus-chimaera in the Gorstian Stage, leintwardinensis, tenuis and formosus in the Ludfordian Stage and parultimus-ultimus and perneri in the Přidoli Series.
{"title":"Upper Silurian (Gorstian, Ludfordian, PŘÍDOLÍ) Graptolite Biozonation in the Muhurr area (Albania)","authors":"P. Pashko","doi":"10.12681/BGSG.21688","DOIUrl":"https://doi.org/10.12681/BGSG.21688","url":null,"abstract":"Three stratigraphical sections and several outcrops through the upper Silurian graptolite shales of the Muhurr area, Albania have been revised. Based on a new detailed re-examination and re-evaluation of graptolite collections and previously unpublished and published studies, a biozonal scheme with much new biostratigraphical data is established. The graptolite assemblages are dominated by Monograptidae: Neodiversograptus, Saetograptus, Bohemograptus, Colonograptus, Pseudomonoclimacis and Lobograptus which are associated with several Retiolitidae. A total of 37 graptolite species has been identified; selected important species are illustrated. The present study recognized and defined the following seven upper Silurian graptolite biozones: nilssoni and scanicus-chimaera in the Gorstian Stage, leintwardinensis, tenuis and formosus in the Ludfordian Stage and parultimus-ultimus and perneri in the Přidoli Series.","PeriodicalId":9519,"journal":{"name":"Bulletin of the Geological Society of Greece","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75274218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
George Kontokostas, A. Antonarakou, Marisa Fountopoulou, H. Drinia, S. Lozios
The limited exploitation and low understanding of geological notions, in modern education in physical sciences, motivated the planning of research procedures about the understanding of rock formations, of recognizing rocks, of informing about geological and hydrographic potential, for students of secondary school of Attica, using techniques entailed in the scientific/educational methodology by inquiry, suggesting educational walking paths through the historical center of Athens. Selected places of the walk trail served our educational aims. Via the educational intervention, students improved their understanding of geological notions, their creativity, their cooperation and their critical thinking. The educational walk trail motivated the students’ interest in the science of geology.
{"title":"Urban geology: educational proposal for Geoscience. a case study from the inner city of Athens, Greece.","authors":"George Kontokostas, A. Antonarakou, Marisa Fountopoulou, H. Drinia, S. Lozios","doi":"10.12681/BGSG.21002","DOIUrl":"https://doi.org/10.12681/BGSG.21002","url":null,"abstract":"The limited exploitation and low understanding of geological notions, in modern education in physical sciences, motivated the planning of research procedures about the understanding of rock formations, of recognizing rocks, of informing about geological and hydrographic potential, for students of secondary school of Attica, using techniques entailed in the scientific/educational methodology by inquiry, suggesting educational walking paths through the historical center of Athens. Selected places of the walk trail served our educational aims. Via the educational intervention, students improved their understanding of geological notions, their creativity, their cooperation and their critical thinking. The educational walk trail motivated the students’ interest in the science of geology.","PeriodicalId":9519,"journal":{"name":"Bulletin of the Geological Society of Greece","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85467369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The coastal karst system of Evia Island is developed due to the extended presence of carbonate formations, discharges into the sea either at the coastal zone or via submarine springs, having a direct relation to the tectonic system of the area. Thermal infrared remote sensing has been proved its capability in monitoring thermal differentiations of coastal water plumes. This work aims to locate the freshwater outflows through remote sensing and specific with the use of Landsat’s 8 thermal images and to reveal how the lineaments of the area control this karstification process. L8 contains two thermal bands (Band 10, high gain and Band 11, low gain) with resolution 30m which record the scattering of infrared radiation from the sea surface. Spectral Band 10 was selected due to the high gain characteristics which provide more suitable radiometric resolution (sensitivity). Finally, combing thermal images with geological maps, sea surface temperature (SST) maps have been created.
{"title":"Thermal Remote Sensing for Water Outflows Detection and Determination of the Role of Lineaments in Underground Hydrodynamics of Evia Island, Central Greece","authors":"Laoura Athanasiadou, E. Psomiadis, G. Stamatis","doi":"10.12681/BGSG.20948","DOIUrl":"https://doi.org/10.12681/BGSG.20948","url":null,"abstract":"The coastal karst system of Evia Island is developed due to the extended presence of carbonate formations, discharges into the sea either at the coastal zone or via submarine springs, having a direct relation to the tectonic system of the area. Thermal infrared remote sensing has been proved its capability in monitoring thermal differentiations of coastal water plumes. This work aims to locate the freshwater outflows through remote sensing and specific with the use of Landsat’s 8 thermal images and to reveal how the lineaments of the area control this karstification process. L8 contains two thermal bands (Band 10, high gain and Band 11, low gain) with resolution 30m which record the scattering of infrared radiation from the sea surface. Spectral Band 10 was selected due to the high gain characteristics which provide more suitable radiometric resolution (sensitivity). Finally, combing thermal images with geological maps, sea surface temperature (SST) maps have been created.","PeriodicalId":9519,"journal":{"name":"Bulletin of the Geological Society of Greece","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80718930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Filippidis, Christina Mytiglaki, N. Kantiranis, A. Tsirambides
Fifteen (15) zeolitic rocks from Karlovassi-Marathokampos basin of Samos Island (Greece) were investigated for their mineralogical composition by X-Ray Diffraction (XRD) method. According to EU Regulation No 651/2013, clinoptilolite of sedimentary origin with ≥80 wt% clinoptilolite, ≤20 wt% clay minerals, free of fibres and quartz, can be used as feed additive for all animal species. Depending on the zeolites, the zeolitic rocks are grouped to those containing: Clinoptilolite (33-86 wt%), clinoptilolite (59 wt%) + mordenite (20-21 wt%), clinoptilolite (22 wt%) + analcime (29 wt%), clinoptilolite (17 wt%) + phillipsite (27 wt%), analcime (29-70 wt%), mordenite (62%) and chabazite (63 wt%). None of the clinoptilolite-containing rocks (10 samples) meet the requirements of the EU Regulation No 651/2013, and thus cannot be used as feed additives for all animal species and consequently as nutrition supplements, since all of them contain 2-5 wt% quartz, two of them 20-21 wt% mordenite (fibrous zeolite), nine of them <80 wt% clinoptilolite (17-73 wt%) and two of them >20 wt% clay minerals (27-42 wt%). Although the EU Regulation No 651/2013 refers to clinoptilolite of sedimentary origin, using the presence or absence of quartz and fibrous minerals, none of the five mordenite, analcime and chabazite containing zeolitic rocks, can be used as feed additives and nutrition supplements, since all of them contain 2-6 wt% quartz and one of them contains 62 wt% mordenite (fibrous zeolite).
{"title":"The Mineralogical Composition of Samos Zeoliitic Rocks and their potential use as Feed Additives and Nutrition Supplements","authors":"A. Filippidis, Christina Mytiglaki, N. Kantiranis, A. Tsirambides","doi":"10.12681/bgsg.20706","DOIUrl":"https://doi.org/10.12681/bgsg.20706","url":null,"abstract":"Fifteen (15) zeolitic rocks from Karlovassi-Marathokampos basin of Samos Island (Greece) were investigated for their mineralogical composition by X-Ray Diffraction (XRD) method. According to EU Regulation No 651/2013, clinoptilolite of sedimentary origin with ≥80 wt% clinoptilolite, ≤20 wt% clay minerals, free of fibres and quartz, can be used as feed additive for all animal species. Depending on the zeolites, the zeolitic rocks are grouped to those containing: Clinoptilolite (33-86 wt%), clinoptilolite (59 wt%) + mordenite (20-21 wt%), clinoptilolite (22 wt%) + analcime (29 wt%), clinoptilolite (17 wt%) + phillipsite (27 wt%), analcime (29-70 wt%), mordenite (62%) and chabazite (63 wt%). None of the clinoptilolite-containing rocks (10 samples) meet the requirements of the EU Regulation No 651/2013, and thus cannot be used as feed additives for all animal species and consequently as nutrition supplements, since all of them contain 2-5 wt% quartz, two of them 20-21 wt% mordenite (fibrous zeolite), nine of them <80 wt% clinoptilolite (17-73 wt%) and two of them >20 wt% clay minerals (27-42 wt%). Although the EU Regulation No 651/2013 refers to clinoptilolite of sedimentary origin, using the presence or absence of quartz and fibrous minerals, none of the five mordenite, analcime and chabazite containing zeolitic rocks, can be used as feed additives and nutrition supplements, since all of them contain 2-6 wt% quartz and one of them contains 62 wt% mordenite (fibrous zeolite).","PeriodicalId":9519,"journal":{"name":"Bulletin of the Geological Society of Greece","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81403012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Dura, T. Mertzimekis, E. Bakalis, P. Nomikou, Andreas Gondikas, M. Hannington, S. Petersen
Almost three quarters of known volcanic activity on Earth occurs in underwater locations. The presence of active hydrothermal vent fields in such environments is a potential natural hazard for the environment, the society, and the economy. Despite its importance for risk assessment and risk mitigation, monitoring of the activity is impeded by the remoteness and the extreme conditions of underwater volcanoes. The large difference of population present on Santorini between the winter and summer seasons, all within a partially enclosed system, make the Santorini-Kolumbo volcanic field, an ideal place for detailed exploration. In 2017, GEOMAR in collaboration with the National and Kapodistrian University of Athens (mission: POS-510 ANYDROS), used an Autonomous Underwater Vehicle (AUV) to map the NE–trending Santorini–Kolumbo line, where it also collected CTD data. Here we present the preliminary results from the 15-hour survey held on the 25th March 2017, during the POS-510 expedition targeting the vent field which is located in the North Basin of Santorini Caldera. Detailed CTD 3D profiles have been reconstructed from the raw data of Santorini’s vent field. An anomaly emerges at the depth of 350 m in the Conductivity and Salinity depth profiles, as the CTD sensor is placed directly above the vent sources. Anomalies were evident in the 3D maps reconstructed, showing for the first time a rather weak, but underlying hydrothermal vent activity at various locations. As the present results are the first ones produced from this expedition, further investigation is required incorporating the full dataset. Based on those results, the impact of developing appropriate mechanisms and policies to avoid the associated natural hazard is expected to be immense.
{"title":"CTD data profiling to assess the natural hazard of active submarine vent fields: the case of Santorini Island","authors":"A. Dura, T. Mertzimekis, E. Bakalis, P. Nomikou, Andreas Gondikas, M. Hannington, S. Petersen","doi":"10.12681/BGSG.20942","DOIUrl":"https://doi.org/10.12681/BGSG.20942","url":null,"abstract":"Almost three quarters of known volcanic activity on Earth occurs in underwater locations. The presence of active hydrothermal vent fields in such environments is a potential natural hazard for the environment, the society, and the economy. Despite its importance for risk assessment and risk mitigation, monitoring of the activity is impeded by the remoteness and the extreme conditions of underwater volcanoes. The large difference of population present on Santorini between the winter and summer seasons, all within a partially enclosed system, make the Santorini-Kolumbo volcanic field, an ideal place for detailed exploration. In 2017, GEOMAR in collaboration with the National and Kapodistrian University of Athens (mission: POS-510 ANYDROS), used an Autonomous Underwater Vehicle (AUV) to map the NE–trending Santorini–Kolumbo line, where it also collected CTD data. Here we present the preliminary results from the 15-hour survey held on the 25th March 2017, during the POS-510 expedition targeting the vent field which is located in the North Basin of Santorini Caldera. Detailed CTD 3D profiles have been reconstructed from the raw data of Santorini’s vent field. An anomaly emerges at the depth of 350 m in the Conductivity and Salinity depth profiles, as the CTD sensor is placed directly above the vent sources. Anomalies were evident in the 3D maps reconstructed, showing for the first time a rather weak, but underlying hydrothermal vent activity at various locations. As the present results are the first ones produced from this expedition, further investigation is required incorporating the full dataset. Based on those results, the impact of developing appropriate mechanisms and policies to avoid the associated natural hazard is expected to be immense.","PeriodicalId":9519,"journal":{"name":"Bulletin of the Geological Society of Greece","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85254360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christina Mytiglaki, N. Kantiranis, P. Misaelides, F. Noli, A. Filippidis
Specific continuous layers of zeolitic tuff in Ntrista stream location of Petrota area of Evros region (NA11) and pure natural crystals of heulandite (HEU1) from the collection of the Department of Mineralogy-Petrology-Economic Geology, School of Geology, Aristotle University of Thessaloniki, have been investigated. The X-Ray Diffraction analyses showed that the sample NA11 consists of 86 wt% HEU-type zeolite, 4 wt% micas+ clay-minerals, 4 wt% quartz, 2 wt% christobalite and 4 wt% feldspars, while the sample HEU1 is pure heulandite crystal. The mineral-chemistry was determined by SEM-EDS microanalyses. The zeolite of the NA11 sample is Ca-rich clinoptilolite and its chemical formulae is Ca 1.8 K 1.0 Mg 0.7 Na 0.5 Al 6.4 Si 29.5 O 72 ·21H 2 O, while the zeolite of the sample HEU1 is heulandite and its chemical formulae is Ca 3.6 Na 1.0 Κ 0.2 Sr 0.2 Ba 0.1 Al 8.1 Si 27.6 O 72 ·21H 2 O. The uptake ability of the samples was measured by the AMAS method (Ammonium Acetate Saturation). The two examined materials show high uptake ability. The measured value for the zeolitic tuff NA11 is 231 meq/100g, while for the heulandite crystal (HEU1) is 296 meq/100g. For the determination of the cesium sorption a CsNO 3 solution (concentration 500 mg/L), labelled with small activity of 137 Cs, and pH 2-12 was used. The sorption of the cesium by the two materials, was determined by measuring the gamma radiation emitted by the 137 Cs tracer. The zeolitic tuff presents higher uptake ability of radioactive cesium than the pure heulandite crystal, whereas the sorption of radioactive cesium is not significantly affected by the pH values of the initial solutions in the range pH 2-12.The clinoptilolitic zeolitic tuff NA11 is suitable material for various environmental, agricultural and industrial applications.
研究了Evros地区Petrota地区Ntrista流位置(NA11)的特定连续沸石凝灰岩层和塞萨洛尼基亚里士多德大学地质学院矿物学-岩石学-经济地质系收集的纯天然沸石晶体(HEU1)。x射线衍射分析表明，样品NA11由86 wt%的heu型沸石、4 wt%的云母+粘土矿物、4 wt%的石英、2 wt%的橄榄云石和4 wt%的长石组成，而样品HEU1为纯橄榄云石晶体。采用SEM-EDS显微分析测定矿物化学成分。NA11样品的沸石为富钙斜沸石，分子式为Ca 1.8 K 1.0 Mg 0.7 Na 0.5 Al 6.4 Si 29.5 O 72·21h2o; HEU1样品的沸石为斜沸石，分子式为Ca 3.6 Na 1.0 Κ 0.2 Sr 0.2 Ba 0.1 Al 8.1 Si 27.6 O 72·21h2o。采用AMAS(铵乙酸饱和)法测定样品的吸附能力。这两种材料表现出较高的吸收能力。沸石凝灰岩NA11的测定值为231 meq/100g，沸石凝灰岩(HEU1)的测定值为296 meq/100g。测定铯吸附性时，使用浓度为500 mg/L的cno3溶液，标记为137 Cs的小活性，pH为2-12。通过测量137cs示踪剂发出的伽马辐射来确定两种材料对铯的吸附。沸石凝灰岩对放射性铯的吸收能力高于纯沸石凝灰岩晶体，而初始溶液pH值在pH 2 ~ 12范围内对放射性铯的吸收影响不显著。斜沸石型沸石凝灰岩NA11是一种适合于各种环境、农业和工业应用的材料。
{"title":"COMPARATIVE STUDY OF THE CESIUM UPTAKE ABILITY BETWEEN HEU-TYPE (CLINOPTILOLITE-HEULANDITE) ZEOLITIC TUFF AND PURE HEULANDITE","authors":"Christina Mytiglaki, N. Kantiranis, P. Misaelides, F. Noli, A. Filippidis","doi":"10.12681/BGSG.20707","DOIUrl":"https://doi.org/10.12681/BGSG.20707","url":null,"abstract":"Specific continuous layers of zeolitic tuff in Ntrista stream location of Petrota area of Evros region (NA11) and pure natural crystals of heulandite (HEU1) from the collection of the Department of Mineralogy-Petrology-Economic Geology, School of Geology, Aristotle University of Thessaloniki, have been investigated. The X-Ray Diffraction analyses showed that the sample NA11 consists of 86 wt% HEU-type zeolite, 4 wt% micas+ clay-minerals, 4 wt% quartz, 2 wt% christobalite and 4 wt% feldspars, while the sample HEU1 is pure heulandite crystal. The mineral-chemistry was determined by SEM-EDS microanalyses. The zeolite of the NA11 sample is Ca-rich clinoptilolite and its chemical formulae is Ca 1.8 K 1.0 Mg 0.7 Na 0.5 Al 6.4 Si 29.5 O 72 ·21H 2 O, while the zeolite of the sample HEU1 is heulandite and its chemical formulae is Ca 3.6 Na 1.0 Κ 0.2 Sr 0.2 Ba 0.1 Al 8.1 Si 27.6 O 72 ·21H 2 O. The uptake ability of the samples was measured by the AMAS method (Ammonium Acetate Saturation). The two examined materials show high uptake ability. The measured value for the zeolitic tuff NA11 is 231 meq/100g, while for the heulandite crystal (HEU1) is 296 meq/100g. For the determination of the cesium sorption a CsNO 3 solution (concentration 500 mg/L), labelled with small activity of 137 Cs, and pH 2-12 was used. The sorption of the cesium by the two materials, was determined by measuring the gamma radiation emitted by the 137 Cs tracer. The zeolitic tuff presents higher uptake ability of radioactive cesium than the pure heulandite crystal, whereas the sorption of radioactive cesium is not significantly affected by the pH values of the initial solutions in the range pH 2-12.The clinoptilolitic zeolitic tuff NA11 is suitable material for various environmental, agricultural and industrial applications.","PeriodicalId":9519,"journal":{"name":"Bulletin of the Geological Society of Greece","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74222396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article deals with the hydrochemistry of coastal aquifers of the Oropos plain, Attica, Greece. It is the first study which presents hydrochemical data of the Oropos plain groundwater. Groundwater samples from 34 wells were collected and analyzed for major and heavy metal constituents. Groundwater was differentiated between the Pleistocene confined aquifer and the group of the Holocene, the Miocene and the Mesozoic aquifers based on the electrical conductivity (EC) values and the chlorides content. Groundwater in the Pleistocene sediments presented EC values ranging between 766 and 971 μ S/cm and chlorides between 95-163mg/l. The group of the rest aquifers presented EC values up to 3770 μ S/cm and chlorides up to 993mg/l. The Pleistocene aquifer seems to be protected from seawater intrusion, although, it is located adjacent to the shoreline. In addition, most of the heavy metal concentration exceeded the EU limits. Cd, Fe, Pb, Ni have been determined at 82, 2500, 817, 217 μ g/lit respectively. Groundwater was, also, categorized into 2 main water types that of Ca-Mg-HCO3 type indicating recharge of fresh water and that of Ca-Mg-Cl type indicating reverse cation exchange of old Na-Cl waters.
{"title":"Hydrochemical characteristics of the Oropos coastal aquifers, Attica, Greece","authors":"D. Hermides, Dimitrios Zaxariadis, G. Stamatis","doi":"10.12681/BGSG.20939","DOIUrl":"https://doi.org/10.12681/BGSG.20939","url":null,"abstract":"This article deals with the hydrochemistry of coastal aquifers of the Oropos plain, Attica, Greece. It is the first study which presents hydrochemical data of the Oropos plain groundwater. Groundwater samples from 34 wells were collected and analyzed for major and heavy metal constituents. Groundwater was differentiated between the Pleistocene confined aquifer and the group of the Holocene, the Miocene and the Mesozoic aquifers based on the electrical conductivity (EC) values and the chlorides content. Groundwater in the Pleistocene sediments presented EC values ranging between 766 and 971 μ S/cm and chlorides between 95-163mg/l. The group of the rest aquifers presented EC values up to 3770 μ S/cm and chlorides up to 993mg/l. The Pleistocene aquifer seems to be protected from seawater intrusion, although, it is located adjacent to the shoreline. In addition, most of the heavy metal concentration exceeded the EU limits. Cd, Fe, Pb, Ni have been determined at 82, 2500, 817, 217 μ g/lit respectively. Groundwater was, also, categorized into 2 main water types that of Ca-Mg-HCO3 type indicating recharge of fresh water and that of Ca-Mg-Cl type indicating reverse cation exchange of old Na-Cl waters.","PeriodicalId":9519,"journal":{"name":"Bulletin of the Geological Society of Greece","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73888189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eleni Michailidou, M. Vavelidis, L. Papadopoulou, N. Kantiranis
The present work studies the tuffs associated with the volcanic area of the Paleogene Sheinovets caldera, located on the southeastern part of the Rhodope massif, in Bulgaria. Its purpose is to describe the mineralogical and geochemical composition of the zeolitized volcaniclastic deposits in the broader area of Petrota village, in the northwesternmost part of the Greek regional unit of Evros, in northeast Greece. The samples studied in this work were collected from seven (7) different locations, covering an area of almost 4 km in length and 2 km in width. Macroscopically, the samples display a greyish-green hue and they are widespread in the area of study. They often contain fragments of the crystalline metamorphic basement (mica-schists, phyllites, amphibolites, quartzites) and/or rhyolitic clasts. A rhyolitic outcrop of greyish-pink hue is observed in the Mavri Petra region, probably related to the Rupelian acid volcanism that occurred in the Sheinovets caldera. The mineralogy of the tuffs was studied under light polarizing microscope and using Scanning Electron Microscopy (SEM), and it was further confirmed by X-ray powder diffraction (XRPD) method. The initial matrix of the tuffs consisted predominantly of glass shards that are now partly or fully altered into zeolites and clay minerals, such as celadonite, displaying characteristic pseudomorphic structures. The dominant zeolite is clinoptilolite, while in some areas the presence of mordenite is also noticed. Feldspar phenocrysts are abundant, and they are represented by plagioclase and sanidine. Although quartz crystals can be observed under light-polarizing microscope solely in metamorphic fragments, the presence of silica polymorphs was also confirmed through SEM and XRPD analysis, with quartz and cristobalite prevailing. The mineralogical assemblage includes phenocrysts of biotite and in some cases amphiboles, while pyroxene, epidote, garnet, titanite, apatite, zircon, ilmenite, magnetite and rutile are additional minerals which have been identified locally in accessory quantities. Chemical analysis was carried out for major and trace elements, using the X-ray fluorescence (XRF) method and 4 Acid digestion ICP-MS analysis, respectively. The samples of Mavri Petra region, exhibit high concentrations in Cu, Pb, Mn, V, P and W. The analyzed concentrations of U in the area of Palaeokklisi are relatively high in comparison to the rest due to its proximity to a fault. Towards the northwestern study area, close to the Greek-Bulgarian border, the concentrations of Sr appear to be particularly high, probably because the area is closer to the volcanic centre.
{"title":"Mineralogical and Geochemical Study of the Zeolitized Volcaniclastic Rocks of Petrota region, Evros Prefecture, Northeastern Greece","authors":"Eleni Michailidou, M. Vavelidis, L. Papadopoulou, N. Kantiranis","doi":"10.12681/BGSG.20946","DOIUrl":"https://doi.org/10.12681/BGSG.20946","url":null,"abstract":"The present work studies the tuffs associated with the volcanic area of the Paleogene Sheinovets caldera, located on the southeastern part of the Rhodope massif, in Bulgaria. Its purpose is to describe the mineralogical and geochemical composition of the zeolitized volcaniclastic deposits in the broader area of Petrota village, in the northwesternmost part of the Greek regional unit of Evros, in northeast Greece. The samples studied in this work were collected from seven (7) different locations, covering an area of almost 4 km in length and 2 km in width. Macroscopically, the samples display a greyish-green hue and they are widespread in the area of study. They often contain fragments of the crystalline metamorphic basement (mica-schists, phyllites, amphibolites, quartzites) and/or rhyolitic clasts. A rhyolitic outcrop of greyish-pink hue is observed in the Mavri Petra region, probably related to the Rupelian acid volcanism that occurred in the Sheinovets caldera. The mineralogy of the tuffs was studied under light polarizing microscope and using Scanning Electron Microscopy (SEM), and it was further confirmed by X-ray powder diffraction (XRPD) method. The initial matrix of the tuffs consisted predominantly of glass shards that are now partly or fully altered into zeolites and clay minerals, such as celadonite, displaying characteristic pseudomorphic structures. The dominant zeolite is clinoptilolite, while in some areas the presence of mordenite is also noticed. Feldspar phenocrysts are abundant, and they are represented by plagioclase and sanidine. Although quartz crystals can be observed under light-polarizing microscope solely in metamorphic fragments, the presence of silica polymorphs was also confirmed through SEM and XRPD analysis, with quartz and cristobalite prevailing. The mineralogical assemblage includes phenocrysts of biotite and in some cases amphiboles, while pyroxene, epidote, garnet, titanite, apatite, zircon, ilmenite, magnetite and rutile are additional minerals which have been identified locally in accessory quantities. Chemical analysis was carried out for major and trace elements, using the X-ray fluorescence (XRF) method and 4 Acid digestion ICP-MS analysis, respectively. The samples of Mavri Petra region, exhibit high concentrations in Cu, Pb, Mn, V, P and W. The analyzed concentrations of U in the area of Palaeokklisi are relatively high in comparison to the rest due to its proximity to a fault. Towards the northwestern study area, close to the Greek-Bulgarian border, the concentrations of Sr appear to be particularly high, probably because the area is closer to the volcanic centre.","PeriodicalId":9519,"journal":{"name":"Bulletin of the Geological Society of Greece","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91517206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Near-Infrared spectroscopy (NIR) is a useful tool for direct and on-site identification of rock mineralogy in spite of the difficulties arising in spectral evaluation, due to limited availability of spectral libraries at the time. Especially in the field, a functional methodology for the identification and evaluation if possible, of the geologic materials, is of interest to many researchers. However, several different parameters (such as grain size, color, mineralogy, texture, water content etc.) can affect the spectroscopic properties of the samples resulting in spectral variability. The subject of the present work focuses in various lithotypes (monzodiorite, diorite, altered diorite, actinolite schist, cataclasite, slate) from Kos Island, Aegean Sea, in Greece, all bearing hydrous minerals in various amounts. The evaluation of the results obtained from NIR spectroscopy offered important qualitative information about the mineralogy of the lithotypes examined. The important asset of the method is that no sample preparation was necessary. From the reflectance spectra, the NIR-active minerals that were identified include chlorite, micas, amphiboles and epidotes. Petrographic and mineralogic analyses were also employed in order to confirm the NIR results and provide more detailed information about the mineralogy of the samples, the grain size and the orientation of the minerals. Correlation of wavelength positions at ~1400 nm with loss on ignition (LOI) values led us to relate the various lithotypes in terms of their petrological affinities. NIR spectroscopy was proved to be a useful tool, especially for the mineralogic identification of rocks underwent low- to medium grade metamorphism, from greenschist to amphibolite facies.
{"title":"Application of Near-Infrared Spectroscopy for the identification of rock mineralogy from Kos Island, Aegean Sea, Greece","authors":"M. Kokkaliari, I. Iliopoulos","doi":"10.12681/bgsg.20708","DOIUrl":"https://doi.org/10.12681/bgsg.20708","url":null,"abstract":"Near-Infrared spectroscopy (NIR) is a useful tool for direct and on-site identification of rock mineralogy in spite of the difficulties arising in spectral evaluation, due to limited availability of spectral libraries at the time. Especially in the field, a functional methodology for the identification and evaluation if possible, of the geologic materials, is of interest to many researchers. However, several different parameters (such as grain size, color, mineralogy, texture, water content etc.) can affect the spectroscopic properties of the samples resulting in spectral variability. The subject of the present work focuses in various lithotypes (monzodiorite, diorite, altered diorite, actinolite schist, cataclasite, slate) from Kos Island, Aegean Sea, in Greece, all bearing hydrous minerals in various amounts. The evaluation of the results obtained from NIR spectroscopy offered important qualitative information about the mineralogy of the lithotypes examined. The important asset of the method is that no sample preparation was necessary. From the reflectance spectra, the NIR-active minerals that were identified include chlorite, micas, amphiboles and epidotes. Petrographic and mineralogic analyses were also employed in order to confirm the NIR results and provide more detailed information about the mineralogy of the samples, the grain size and the orientation of the minerals. Correlation of wavelength positions at ~1400 nm with loss on ignition (LOI) values led us to relate the various lithotypes in terms of their petrological affinities. NIR spectroscopy was proved to be a useful tool, especially for the mineralogic identification of rocks underwent low- to medium grade metamorphism, from greenschist to amphibolite facies.","PeriodicalId":9519,"journal":{"name":"Bulletin of the Geological Society of Greece","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72650589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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