{"title":"Porosity structure of Icelandic basalt","authors":"Ó. Sigurdsson, V. Stefansson","doi":"10.3176/geol.2002.1.03","DOIUrl":"https://doi.org/10.3176/geol.2002.1.03","url":null,"abstract":"","PeriodicalId":237994,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Geology","volume":"47 24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129003520","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":"HOLOCENE ENVIRONMENTAL EVENTS IN THE VIITNA AREA, NORTH ESTONIA","authors":"L. Saarse, A. Poska, E. Kaup, A. Heinsalu","doi":"10.3176/geol.1998.1.03","DOIUrl":"https://doi.org/10.3176/geol.1998.1.03","url":null,"abstract":"","PeriodicalId":237994,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Geology","volume":"126 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124635855","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}
. In mainland Estonia the Muhu Formation of the Jaagarahu Stage (Silurian, Wenlock) is represented by secondary dolomites (dolostones) originating from the normal-marine calcareous sediments of the shoal facies belt of the palaeobasin. Five rock types, reef, breccia, microcrystalline, low-argillaceous, and argillaceous dolomites, differing in the lithological composition, properties, and possible fields of use, are distinguished. The chemical composition ofdolomites exhibits close to ideal molar proportions of Ca and Mg for all above-mentioned types of dolomites. The results of the X-ray diffraction study show that dolomites are nearly stoichiometric, with d,,, equalling 2.8850-2.8856 А. The dolomites studied represent the most completely and evenly dolomitized part of the extensive body of pervasive Silurian dolomites.
{"title":"DOLOMITES OF THE MUHU FORMATION (SILURIAN) IN MAINLAND ESTONIA - ASPECTS OF DOLOMITIZATION, PROPERTIES, AND PROSPECTS OF UTILIZATION","authors":"A. Teedumäe, T. Kiipli, T. Kallaste","doi":"10.3176/geol.1999.4.02","DOIUrl":"https://doi.org/10.3176/geol.1999.4.02","url":null,"abstract":". In mainland Estonia the Muhu Formation of the Jaagarahu Stage (Silurian, Wenlock) is represented by secondary dolomites (dolostones) originating from the normal-marine calcareous sediments of the shoal facies belt of the palaeobasin. Five rock types, reef, breccia, microcrystalline, low-argillaceous, and argillaceous dolomites, differing in the lithological composition, properties, and possible fields of use, are distinguished. The chemical composition ofdolomites exhibits close to ideal molar proportions of Ca and Mg for all above-mentioned types of dolomites. The results of the X-ray diffraction study show that dolomites are nearly stoichiometric, with d,,, equalling 2.8850-2.8856 А. The dolomites studied represent the most completely and evenly dolomitized part of the extensive body of pervasive Silurian dolomites.","PeriodicalId":237994,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Geology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129904338","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}
. Mineralogy of apatite in the scales of Recent sharks, rays, and teleosts was studied using X-ray diffraction analysis. All the studied fish scales are composed of hydroxyapatite with different lattice parameters. The apatite in the scales ofRecent rays and teleosts has lattice parameters within the range of a=9.44-9.46 апа с = 6.87-6.88, which is comparable to the apatite in Recent vertebrate bones. The shark scale apatite has lattice parameters a = 9.40-9.41 and c = 6.87-6.88, closer to the apatite in Recent lingulate brachiopod shells. The distinct lattice parameters reflect differences in the chemical composition, first of all, in the content of hydroxyl, fluorine, and carbonate anions. These differences between the higher taxa of Recent fishes are significant from an evolutionary perspective and have implications to the interpretation of the mineralogy of fossil vertebrate skeletons.
{"title":"HYDROXYAPATITE VARIETIES IN RECENT FISH SCALES","authors":"J. Nemliher, T. Kallaste, I. Puura","doi":"10.3176/geol.1997.4.03","DOIUrl":"https://doi.org/10.3176/geol.1997.4.03","url":null,"abstract":". Mineralogy of apatite in the scales of Recent sharks, rays, and teleosts was studied using X-ray diffraction analysis. All the studied fish scales are composed of hydroxyapatite with different lattice parameters. The apatite in the scales ofRecent rays and teleosts has lattice parameters within the range of a=9.44-9.46 апа с = 6.87-6.88, which is comparable to the apatite in Recent vertebrate bones. The shark scale apatite has lattice parameters a = 9.40-9.41 and c = 6.87-6.88, closer to the apatite in Recent lingulate brachiopod shells. The distinct lattice parameters reflect differences in the chemical composition, first of all, in the content of hydroxyl, fluorine, and carbonate anions. These differences between the higher taxa of Recent fishes are significant from an evolutionary perspective and have implications to the interpretation of the mineralogy of fossil vertebrate skeletons.","PeriodicalId":237994,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Geology","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127010919","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}
. It has been ascertained that the regional upliit anomaly which was established by Svensson (1989
。确定了Svensson(1989)建立的区域隆起异常
{"title":"GEOLOGICAL BACKGROUND OF THE PRESENT REGIONAL UPLIFT ANOMALY IN ESTONIA","authors":"A. Miidel","doi":"10.3176/geol.1994.2.02","DOIUrl":"https://doi.org/10.3176/geol.1994.2.02","url":null,"abstract":". It has been ascertained that the regional upliit anomaly which was established by Svensson (1989","PeriodicalId":237994,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Geology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129284577","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":"РЕГРЕССИОННЫЙ АНАЛИЗ В ЭКСПОНЕНЦИАЛЬНОЙ МОДЕЛИ ФОРМИРОВАНИЯ ПАЛЕОДОЗЫ","authors":"G. Hütt, V. Polyakov","doi":"10.3176/geol.1990.3.06","DOIUrl":"https://doi.org/10.3176/geol.1990.3.06","url":null,"abstract":"","PeriodicalId":237994,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Geology","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123822070","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":"ПОГРАНИЧНЫЕ КЕМБРО-ОРДОВИКСКИЕ ОТЛОЖЕНИЯ РАЗРЕЗА САКА П В СЕВЕРО-ВОСТОЧНОЙ ЭСТОНИИ","authors":"H. Heinsalu, I. Paalits, V. Viira","doi":"10.3176/geol.1991.1.02","DOIUrl":"https://doi.org/10.3176/geol.1991.1.02","url":null,"abstract":"","PeriodicalId":237994,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Geology","volume":"7 19","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120824619","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}
. Carbon isotope data fromsix borehole sections ofEstonia and West Latvia are presented and analysed against different geological and palaeontological phenomena in order to understand possible reasons for shifts in B'°C values. Four most important carbon isotopic events are established -in the Llandovery (from bottom): (1) a negative shift (-0.5 to —1.5%0) in the Coronograptus cyphus Zone (in the Pusku Beds), (2) a positive excursion (+3.0 to +4.0%0) in the Demirastrites triangulatus Zone (Ikla Member), (3) a negative excursion (—1.3 to —1.4%0) in the Stimulograptus sedgwickii Zone (Rumba Formation), (4) a small positive shift at the beginning of the Velise Formation in the Spirograptus guerichi-Streptograptus crispus Zone. The positive excursions seem to correspond to certain glacial events, negative ones to humid climatic episodes with rising sea level. In the case of the Rumba Formation the influence of carbon with low 5С released due to volcanic activity in the late Aeronian is suggested. The background carbon isotope values are relatively stable during the Llandovery, showing some changes in correlation with facies and climate controlled stratigraphical units.
{"title":"CARBON ISOTOPIC COMPOSITION OF LLANDOVERY ROCKS (EAST BALTIC SILURIAN) WITH ENVIRONMENTAL INTERPRETATION","authors":"D. Kaljo, T. Martma","doi":"10.3176/geol.2000.4.02","DOIUrl":"https://doi.org/10.3176/geol.2000.4.02","url":null,"abstract":". Carbon isotope data fromsix borehole sections ofEstonia and West Latvia are presented and analysed against different geological and palaeontological phenomena in order to understand possible reasons for shifts in B'°C values. Four most important carbon isotopic events are established -in the Llandovery (from bottom): (1) a negative shift (-0.5 to —1.5%0) in the Coronograptus cyphus Zone (in the Pusku Beds), (2) a positive excursion (+3.0 to +4.0%0) in the Demirastrites triangulatus Zone (Ikla Member), (3) a negative excursion (—1.3 to —1.4%0) in the Stimulograptus sedgwickii Zone (Rumba Formation), (4) a small positive shift at the beginning of the Velise Formation in the Spirograptus guerichi-Streptograptus crispus Zone. The positive excursions seem to correspond to certain glacial events, negative ones to humid climatic episodes with rising sea level. In the case of the Rumba Formation the influence of carbon with low 5С released due to volcanic activity in the late Aeronian is suggested. The background carbon isotope values are relatively stable during the Llandovery, showing some changes in correlation with facies and climate controlled stratigraphical units.","PeriodicalId":237994,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Geology","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121203813","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":"THE BILLINGEN AND VOLKHOV STAGES IN THE NORTHERN EAST BALTIC. DETAILED STRATIGRAPHY AND LITHOFACIES ZONATION","authors":"L. Ainsaar, A. Dronov, T. Meidla, O. Tinn","doi":"10.3176/geol.2000.1.01","DOIUrl":"https://doi.org/10.3176/geol.2000.1.01","url":null,"abstract":"","PeriodicalId":237994,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Geology","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116309291","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":"БИОСТРАТИГРАФИЯ ПОГРАНИЧНЫХ ОТЛОЖЕНИЙ НИЖНЕГО И СРЕДНЕГО КЕМБРИЯ В ЛИТВЕ","authors":"T. Jankauskas","doi":"10.3176/geol.1991.4.03","DOIUrl":"https://doi.org/10.3176/geol.1991.4.03","url":null,"abstract":"","PeriodicalId":237994,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Geology","volume":"87 27 Pt 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126305480","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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