{"title":"Zonal tennantite-tetrahedrites from the Chelopech deposit: a SEM-EDS study","authors":"Victoria Vangelova, Georgy Lutov","doi":"10.52215/rev.bgs.2022.83.3.55","DOIUrl":"https://doi.org/10.52215/rev.bgs.2022.83.3.55","url":null,"abstract":"The composition and structure of tennantite-tetrahedrites from blocks 17 and 18 of the copper-gold high to intermediate sulphidation Chelopech deposit were determined by SEM-EDS. Based on 31 analyses is determined that the tennantites are mostly ferrous, while the tetrahedrites are zinc-rich. In zonal tennantite-tetrahedrite aggregates, sharp saw-shape chalcopyrite bands are evidence of coupled dissolution-precipitation reactions, during the replacement of the former. The fine oscillatory zoning in other tennantite crystals also is related predominantly to internal “self-organization” processes rather than external. In some cases, however, the irregular boundaries between tennantite matrix and tetrahedrite rims and strips and their variable thickness could be due to uneven penetration of fluid into the crystal along the weak zones as a result of replacement rather than overgrowth.","PeriodicalId":40733,"journal":{"name":"Spisanie Na B Lgarskoto Geologichesko Druzhestov-Review of the Bulgarian Geological Society","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47176446","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}
{"title":"Quantitative Holocene palaeolandscape reconstructions in the Beloslav Lake area using pollen data, modelling and simulation approach","authors":"S. Vergiev","doi":"10.52215/rev.bgs.2022.83.3.161","DOIUrl":"https://doi.org/10.52215/rev.bgs.2022.83.3.161","url":null,"abstract":"Pollen records from lacustrine core Bel-1 obtained from the Beloslav Lake (Northeastern Bulgaria) were used to reconstruct the past vegetation and to simulate past landscapes. Numerous 50 km by 30 km landscape simulations were performed at different time windows in the past. Eleven of them were chosen as significant for vegetation dynamics, human impact, and landscape evolution. Comparison of actual and simulated modern vegetation composition showed similar results, which proved the reliability of models. Quantitative reconstructions in the region of the Beloslav Lake showed a clear trend of decreasing forest landscapes at the expense of agrarian ones. Simulated landscapes based on quantitative reconstruction of vegetation coverage reflected a more significant anthropogenic impact and openness than those shown by pollen percentages.","PeriodicalId":40733,"journal":{"name":"Spisanie Na B Lgarskoto Geologichesko Druzhestov-Review of the Bulgarian Geological Society","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46179817","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}
I. Kostova, Ralica Sabeva, Gergana Velyanova, Elena Isaeva
{"title":"Cadmium concentrations in coals and fly ashes from coal fired thermoelectric power plants in Bulgaria","authors":"I. Kostova, Ralica Sabeva, Gergana Velyanova, Elena Isaeva","doi":"10.52215/rev.bgs.2022.83.3.101","DOIUrl":"https://doi.org/10.52215/rev.bgs.2022.83.3.101","url":null,"abstract":"The goal of the present study is to present new data regarding concentration and distribution of Cd in feed coals and fly ashes from seven Bulgarian coal fired thermoelectric power plans (TPPs). The study was performed on feed coals and fly ashes collected from Maritza East 2, Maritza East 3, Maritza 3, Republika, Bobov Dol, Varna and Russe TPPs. Bulk fly ash from Maritza East 2 and Maritza East 3 TPPs were obtained and fly ashes from each row of electrostatic precipitators (ESPs) of Maritza 3, Republika, Bobov Dol, Varna and Russe TPPs were also collected. Feed coals from bunkers were sampled at each TPPs. The Cd was determined by using ICP-MS. The present investigation shows that the concentration of Cd in studied coal and fly ashes from almost all TPPs is around the average or lower than Cd content in comparison with Clark values. The exceptions are the fly ashes from the 2-nd and 3-rd row of ESPs from Maritza 3 TPP, where up to 2.5 times higher Cd content was registered. This study shows that Cd concentration in fly ashes gradually increases from the 1st to 3rd and 5th-row of ESP from almost all sampled thermoelectric power plants, whence the conclusion that Cd content increases significantly and is mainly concentrated in the finest fly ash particles.","PeriodicalId":40733,"journal":{"name":"Spisanie Na B Lgarskoto Geologichesko Druzhestov-Review of the Bulgarian Geological Society","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44701475","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}
{"title":"Degree of Pyritization (DOP) and Indicator of Anoxicity (IA) in Jurassic sedimentary rocks from Bulgaria","authors":"L. Metodiev, M. Georgieva, T. Stoylkova","doi":"10.52215/rev.bgs.2022.83.3.149","DOIUrl":"https://doi.org/10.52215/rev.bgs.2022.83.3.149","url":null,"abstract":"The Degree of Pyritization (DOP) and the Indicator of Anoxicity (IA) were used as tools to assess the degree of redox conditions in Lower and Middle Jurassic strata from Bulgaria. Normally-oxygenated (with DOP values < 0.45 and IA values < 0.4), oxygen-restricted (0.45 < DOP < 0.7; 0.4 < IA < 0.5), and oxygen-depleted (DOP > 0.7 and IA > 0.5) bottom-water conditions were recognized on a selection of samples, mainly from the Ozirovo Formation (upper Pliensbachian–Toarcian), but also from the Etropole Formation (lower Bajocian). DOP and IA yielded the highest values (> 0.9 for DOP and > 0.5 for IA) from samples of the lower Toarcian Tenuicostatum and Falciferum ammonite zones, and thus, denoted declined oxygen levels and enrichment of reactive Fe at the sea floor. Beyond this stratigraphic level, both parameters indicated for prevailing normally-oxygenated to oxygen-restricted setting, with limitedly imposed environments beneath stratified water-column.","PeriodicalId":40733,"journal":{"name":"Spisanie Na B Lgarskoto Geologichesko Druzhestov-Review of the Bulgarian Geological Society","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43272794","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}
K. Bogdanov, T. Dönsberg, T. Kääriäinen, Francisco Senna Vieira, M. Mekhrengin, Stefan Velev, Y. Georgieva
{"title":"AHS mapping for hydrothermal alterations detection and mineral deposits exploration","authors":"K. Bogdanov, T. Dönsberg, T. Kääriäinen, Francisco Senna Vieira, M. Mekhrengin, Stefan Velev, Y. Georgieva","doi":"10.52215/rev.bgs.2022.83.3.171","DOIUrl":"https://doi.org/10.52215/rev.bgs.2022.83.3.171","url":null,"abstract":"The Actve Hyperspectral Sensing (AHS) application for a mineral mapping have been tested on outcrops with porphyry-copper style of mineralization in the Vlaykov Vruh and Tsar Assen deposits. As a new tool used in mineral exploration AHS reveals the advantages for mineral detection and targeting as an express new innovative technology and efficient tool for mineral prospecting.","PeriodicalId":40733,"journal":{"name":"Spisanie Na B Lgarskoto Geologichesko Druzhestov-Review of the Bulgarian Geological Society","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43717247","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}
{"title":"Archaemineralogical study of plasters and paints from the Thracian tomb Maglizh (4th–3rd century BC), Bulgaria","authors":"E. Tarassova, M. Tarassov","doi":"10.52215/rev.bgs.2022.83.3.338","DOIUrl":"https://doi.org/10.52215/rev.bgs.2022.83.3.338","url":null,"abstract":"Fragments of plasters and paints from the decoration of the chamber and the grave of the Thracian tomb Muglizh (4th–3rd century BC) were studied. It was established that the plasters are two or three-layered and consist of coarse plaster, pink colored plaster and white putty (stucco). The binder in all three layers is a lime prepared from organogenic limestone. Crushed materials from rocks and minerals were used as fillers in the coarse and pink plasters, and only white-colored minerals such as quartz, calcite, albite were used in the stucco. A mixture of red earth ocher and cinnabar was used as pigment in the red paint and pink plaster. For the black paint, a mixture of crushed charcoal and Egyptian blue was used. The binder in the red and black paints is lime. In pink paint, the binding material is gypsum, and the pigment is cinnabar.","PeriodicalId":40733,"journal":{"name":"Spisanie Na B Lgarskoto Geologichesko Druzhestov-Review of the Bulgarian Geological Society","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47686678","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}
R. Vassileva, Svetoslav Petrussenko, V. Grozdev, I. Peytcheva, Yu. V. Plotkina, A. von Quadt
{"title":"Timing of pegmatite emplacement and skarn formation in the Malyovitsa Unit, NW Rila: evidence from zonal grossular crystals","authors":"R. Vassileva, Svetoslav Petrussenko, V. Grozdev, I. Peytcheva, Yu. V. Plotkina, A. von Quadt","doi":"10.52215/rev.bgs.2022.83.3.121","DOIUrl":"https://doi.org/10.52215/rev.bgs.2022.83.3.121","url":null,"abstract":"Contact Ca-skarns are formed in the marbles of the Malyovitsa Lithotectonic Unit as a result of emplacement of crosscutting pegmatite injections in the area of the Dzhendemski Ezera, NW Rila Mt. Large (up to 4 cm), well-shaped garnet crystals dominate the mineral association with additional vesuvianite, diopside, scapolite and zoisite. Garnets were selected for mineralogical, geochemical and U-Pb geochronological study. Their crystals show clear zonal pattern due to variation in the octahedral position (Fe3+/Al3+), although the overall composition defines grossular predominance (72–95 mol.% grossular; 4–24% andradite). Trace-element signatures reveal constant isomorphic incorporation of P, V, Zn, Ga, Ge and Y, REE, HFSE, U. Results from the in-situ U-Pb dating of the studied skarn materials suggest the timing of pegmatite intrusion onto the metamorphic rocks and marble-hosted skarn formation at 58.37±0.70 Ma.","PeriodicalId":40733,"journal":{"name":"Spisanie Na B Lgarskoto Geologichesko Druzhestov-Review of the Bulgarian Geological Society","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48794789","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}
{"title":"Permian–Triassic A-type rhyolites from the Central Balkanides \u0000(Stara Planina Mountains), Bulgaria","authors":"S. Georgiev, A. Lazarova, Eleonora Balkanska","doi":"10.52215/rev.bgs.2022.83.3.77","DOIUrl":"https://doi.org/10.52215/rev.bgs.2022.83.3.77","url":null,"abstract":"The rhyolites from the Central Balkan and Sinite Kamani areas are formed in a close time span from 254.6 to 250.7 Ma, while those next to the village of Vlado Trichkov are a little bit earlier (260.3±1.0 Ma). Both age groups follow the voluminous late Carboniferous to early Permian igneous activity that ceased around 290 Ma. The geochemical characteristics of the Vlado Trichkov dacite are comparable to those from the earlier magmatic event. On the other hand, the rocks from the Central Balkan and Sinite Kamani areas show trends of A-type granitoids. The origin of this magmatic products could be attributed to a crustal melting by mantle-derived melts, penetrating or underplating the crust in a post-orogenic setting during the initial extension and rifting, preceding the opening of the Vardar-Meliata Ocean.","PeriodicalId":40733,"journal":{"name":"Spisanie Na B Lgarskoto Geologichesko Druzhestov-Review of the Bulgarian Geological Society","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42313663","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}