Pub Date : 2023-07-20DOI: 10.24425/agp.2022.140427
Małgorzata Cegiełka, B. Bagiński, R. Macdonald, H. Belkin, J. Kotowski, B. Upton
: Cegiełka, M., Bagiński, B., MacDonald, R., Belkin, H.E., Kotowski, J. and Upton, B.G.J. 2022. Zirconium silicates in a peralkaline granite: a record of the interplay of magmatic and hydrothermal processes (Ilímaussaq complex, Greenland). Acta Geologica Polonica , 72 (2), 235–245. Warszawa. Compositional and textural data are presented for zircon, secondary Zr-silicates, catapleiite and elpidite in a peralkaline granite from the Ilímaussaq complex, south Greenland. The zircon is essentially stoichiometric, with (Zr + Hf + Si) = 1.96–1.98 a.p.f.u. The secondary Zr-silicates show a wide range of Zr/Si atomic ratios (0.13–0.79). The catapleiite varies from close to stoichiometric to a Na-depleted type showing cation deficiency (5.2–5.8 a.p.f.u.). Elpidite shows similar variations (7.2–9.0 a.p.f.u.). Textural relationships between the Zr phases are interpreted to show that magmatic zircon interacted with hydrous fluids exsolved from the magma to form the secondary Zr-silicates. Formation of catapleiite was late-magmatic, in equilibrium with a Na-Si-bearing fluid. This was followed by the crystallization of elpidite, the fluid having a different Na/Si ratio. Both catapleiite and elpidite experienced Na-loss during late-stage hydrothermal alteration.
{"title":"Zirconium silicates in a peralkaline granite: a record of the interplay of magmatic and hydrothermal processes (Ilímaussaq complex, Greenland)","authors":"Małgorzata Cegiełka, B. Bagiński, R. Macdonald, H. Belkin, J. Kotowski, B. Upton","doi":"10.24425/agp.2022.140427","DOIUrl":"https://doi.org/10.24425/agp.2022.140427","url":null,"abstract":": Cegiełka, M., Bagiński, B., MacDonald, R., Belkin, H.E., Kotowski, J. and Upton, B.G.J. 2022. Zirconium silicates in a peralkaline granite: a record of the interplay of magmatic and hydrothermal processes (Ilímaussaq complex, Greenland). Acta Geologica Polonica , 72 (2), 235–245. Warszawa. Compositional and textural data are presented for zircon, secondary Zr-silicates, catapleiite and elpidite in a peralkaline granite from the Ilímaussaq complex, south Greenland. The zircon is essentially stoichiometric, with (Zr + Hf + Si) = 1.96–1.98 a.p.f.u. The secondary Zr-silicates show a wide range of Zr/Si atomic ratios (0.13–0.79). The catapleiite varies from close to stoichiometric to a Na-depleted type showing cation deficiency (5.2–5.8 a.p.f.u.). Elpidite shows similar variations (7.2–9.0 a.p.f.u.). Textural relationships between the Zr phases are interpreted to show that magmatic zircon interacted with hydrous fluids exsolved from the magma to form the secondary Zr-silicates. Formation of catapleiite was late-magmatic, in equilibrium with a Na-Si-bearing fluid. This was followed by the crystallization of elpidite, the fluid having a different Na/Si ratio. Both catapleiite and elpidite experienced Na-loss during late-stage hydrothermal alteration.","PeriodicalId":7030,"journal":{"name":"Acta Geologica Polonica","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44482022","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}
Pub Date : 2023-07-20DOI: 10.24425/agp.2022.142642
J. Dzierżek, L. Lindner, R. Chlebowski, M. Szymanek, Andriy Bogucki, O. Tomeniuk
: Dzierżek, J., Lindner, L., Chlebowski, R., Szymanek, M., Bogucki, A. and Tomeniuk, O. 2022. Depositional conditions of the Upper Younger Loess during the Last Glacial Maximum in central and eastern Europe. Acta Geologica Polonica , 72 (4), 369–389. Warszawa. This paper is a summary of the results of research on the accumulation conditions of the Upper Younger Loess (LMg) in Poland and Bug loess (bg) in Ukraine from the maximum stage (MIS 2) of the Vistulian (Weichselian) Glaciation in central and eastern Europe. These studies included an analysis of the morphological (topographic) situation of the loess cover, its grain size and heavy mineral composition, the preserved structures of loess sed - imentation as well as mollusc and pollen analyses of this loess. They revealed that the accumulation of Upper Younger Loess (UYL) might have been more dependent on the prevailing moisture conditions than previously thought. These conditions could have been caused by cold air masses from an ice sheet and warm air masses from the Mediterranean Sea and Atlantic coming together in the Carpathians and the Holy Cross Mountains and favouring the formation of dust storms and precipitation. In this process, a loading of loess dust (formed from local rocks weathering in periglacial conditions) by atmospheric moisture particles was especially significant. The moist substrate not only favoured the periodic development of vegetation and molluscs but also enabled the interception of dust and the accumulation of an increasingly thick loess cover. Westerly and south-westerly winds predominated in the UYL as indicated by the topographic position of loess patches and the mineral composition of the studied loess. Periodically an increased air circulation from the east and northeast occurred.
{"title":"Depositional conditions of the Upper Younger Loess during the Last Glacial Maximum in central and eastern Europe","authors":"J. Dzierżek, L. Lindner, R. Chlebowski, M. Szymanek, Andriy Bogucki, O. Tomeniuk","doi":"10.24425/agp.2022.142642","DOIUrl":"https://doi.org/10.24425/agp.2022.142642","url":null,"abstract":": Dzierżek, J., Lindner, L., Chlebowski, R., Szymanek, M., Bogucki, A. and Tomeniuk, O. 2022. Depositional conditions of the Upper Younger Loess during the Last Glacial Maximum in central and eastern Europe. Acta Geologica Polonica , 72 (4), 369–389. Warszawa. This paper is a summary of the results of research on the accumulation conditions of the Upper Younger Loess (LMg) in Poland and Bug loess (bg) in Ukraine from the maximum stage (MIS 2) of the Vistulian (Weichselian) Glaciation in central and eastern Europe. These studies included an analysis of the morphological (topographic) situation of the loess cover, its grain size and heavy mineral composition, the preserved structures of loess sed - imentation as well as mollusc and pollen analyses of this loess. They revealed that the accumulation of Upper Younger Loess (UYL) might have been more dependent on the prevailing moisture conditions than previously thought. These conditions could have been caused by cold air masses from an ice sheet and warm air masses from the Mediterranean Sea and Atlantic coming together in the Carpathians and the Holy Cross Mountains and favouring the formation of dust storms and precipitation. In this process, a loading of loess dust (formed from local rocks weathering in periglacial conditions) by atmospheric moisture particles was especially significant. The moist substrate not only favoured the periodic development of vegetation and molluscs but also enabled the interception of dust and the accumulation of an increasingly thick loess cover. Westerly and south-westerly winds predominated in the UYL as indicated by the topographic position of loess patches and the mineral composition of the studied loess. Periodically an increased air circulation from the east and northeast occurred.","PeriodicalId":7030,"journal":{"name":"Acta Geologica Polonica","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46831883","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}
Pub Date : 2023-07-20DOI: 10.24425/agp.2022.143595
Marek Vďačný
: Vďačný, M. and Michalík, J. 2023. Provenance of quartz debris in the Central Western Carpathians at the end of the Triassic, as indicated by cathodoluminescence colours. Acta Geologica Polonica , 73 (1), 103–114. Warszawa. Lithic fragments including quartz grains occur infrequently in the shallow-marine limestone sequence of the Fatra Formation deposited in the tensional intra-shelf depression of the Central Western Carpathians during the Rhaetian. Nevertheless, their study can bring data answering questions of sources, palaeogeodynamic arrange - ment, and processes at the end of the Triassic. In this study, we examined optically the cathodoluminescence (CL) colours of single quartz grains from the Kardolína section (Tatra Mts, Slovakia). These colours reveal a dominance of grains derived from regionally metamorphosed and plutonic rocks. Grains of hydrothermal and pegmatite origin are less frequent. Some of the quartz grains show recycled cement rims suggesting at least a second cycle origin. This sedimentary basin was situated near to the passive margin formed by the Variscan consolidated terrains of the Vindelician Highlands. Our study of the CL colours of quartz grains contributes to the elucidation of the nature of the rocks of the vanished Vindelician mountain belt.
{"title":"Provenance of quartz debris in the Central Western Carpathians at the end of the Triassic, as indicated by cathodoluminescence colours","authors":"Marek Vďačný","doi":"10.24425/agp.2022.143595","DOIUrl":"https://doi.org/10.24425/agp.2022.143595","url":null,"abstract":": Vďačný, M. and Michalík, J. 2023. Provenance of quartz debris in the Central Western Carpathians at the end of the Triassic, as indicated by cathodoluminescence colours. Acta Geologica Polonica , 73 (1), 103–114. Warszawa. Lithic fragments including quartz grains occur infrequently in the shallow-marine limestone sequence of the Fatra Formation deposited in the tensional intra-shelf depression of the Central Western Carpathians during the Rhaetian. Nevertheless, their study can bring data answering questions of sources, palaeogeodynamic arrange - ment, and processes at the end of the Triassic. In this study, we examined optically the cathodoluminescence (CL) colours of single quartz grains from the Kardolína section (Tatra Mts, Slovakia). These colours reveal a dominance of grains derived from regionally metamorphosed and plutonic rocks. Grains of hydrothermal and pegmatite origin are less frequent. Some of the quartz grains show recycled cement rims suggesting at least a second cycle origin. This sedimentary basin was situated near to the passive margin formed by the Variscan consolidated terrains of the Vindelician Highlands. Our study of the CL colours of quartz grains contributes to the elucidation of the nature of the rocks of the vanished Vindelician mountain belt.","PeriodicalId":7030,"journal":{"name":"Acta Geologica Polonica","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47351288","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}
Pub Date : 2023-07-20DOI: 10.24425/agp.2022.140433
Chan-gyu Yun
: Yun, C.G. 2023. A tyrannosaurid pedal ungual from the Williams Fork Formation (Campanian) of Colorado and its implications for the biogeography of Laramidian dinosaurs. Acta Geologica Polonica , 73 (1), 63–72. Warszawa. A right theropod pedal ungual phalanx II-3 from the Campanian Williams Fork Formation of northwestern Colorado is described, and a combination of features, including the large size, tapering distal tip, robust and stout overall form, triangular cross-section, and a relatively flat ventral surface allows a confident referral to Tyrannosauridae Osborn, 1906. Although this specimen was found in a relatively southern state, the proximal articular surface of this ungual is similar to that of Gorgosaurus libratus Lambe, 1914, a taxon found in the northern state, Alberta. Although based on limited evidence, this may suggest that the range of tyrannosaurids considered endemic to the north of Laramidia extended farther south than previously thought.
{"title":"A tyrannosaurid pedal ungual from the Williams Fork Formation (Campanian) of Colorado and its implications for the biogeography of Laramidian dinosaurs","authors":"Chan-gyu Yun","doi":"10.24425/agp.2022.140433","DOIUrl":"https://doi.org/10.24425/agp.2022.140433","url":null,"abstract":": Yun, C.G. 2023. A tyrannosaurid pedal ungual from the Williams Fork Formation (Campanian) of Colorado and its implications for the biogeography of Laramidian dinosaurs. Acta Geologica Polonica , 73 (1), 63–72. Warszawa. A right theropod pedal ungual phalanx II-3 from the Campanian Williams Fork Formation of northwestern Colorado is described, and a combination of features, including the large size, tapering distal tip, robust and stout overall form, triangular cross-section, and a relatively flat ventral surface allows a confident referral to Tyrannosauridae Osborn, 1906. Although this specimen was found in a relatively southern state, the proximal articular surface of this ungual is similar to that of Gorgosaurus libratus Lambe, 1914, a taxon found in the northern state, Alberta. Although based on limited evidence, this may suggest that the range of tyrannosaurids considered endemic to the north of Laramidia extended farther south than previously thought.","PeriodicalId":7030,"journal":{"name":"Acta Geologica Polonica","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47521316","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}
Pub Date : 2023-07-20DOI: 10.24425/AGP.2020.134562
A. Waśkowska, J. Golonka, K. Starzec, M. Cieszkowski
The Campanian–Paleocene Jaworzynka Formation, a part of the Magura Nappe succession in the Polish Outer Carpathians, is described in terms of its detailed litho- and biostratigraphy. The formation stretches along the marginal part of the Siary Unit, from the Jaworzynka stratotype area in the Silesian Beskid Mts up to the Mszana Dolna area in the Beskid Wyspowy Mts. Its equivalent in the Moravskoslezske Beskydy Mts of the Czech Republic is the Solaň Formation. In the stratotype area, the formation displays complex structure. We distinguish four lithological units, i.e. Biotite Sandstone and Shale (I), Shale (II), Mutne Sandstone Member (III) and Thin-bedded Turbidite (IV) and provide the first detailed biostratigraphy of particular units. The first unit forms the most prominent part of the formation. It was deposited in the Middle Campanian–earliest Maastrichtian within the upper part of Caudammina gigantea Zone up to the lower part of the Rzehakina inclusa Zone. The second unit occurs only locally and its age is limited to the Maastrichtian, to the Rzehakina inclusa Zone. The third unit is composed of thick-bedded sandstones that in some parts may form more than the half of the total thickness of the formation. It is Late Maastrichtian–Danian in age and is placed in the upper part of the Rzehakina inclusa Zone and the lower part of the Rzehakina fissistomata Zone. It is usually covered by a thin package of thin-bedded turbiditic sandstone and shales of Danian–Thanetian age with foraminifera of the Rzehakina fissistomata Zone.
{"title":"Campanian–Paleocene Jaworzynka Formation in its type area (Magura Nappe, Outer Carpathians)","authors":"A. Waśkowska, J. Golonka, K. Starzec, M. Cieszkowski","doi":"10.24425/AGP.2020.134562","DOIUrl":"https://doi.org/10.24425/AGP.2020.134562","url":null,"abstract":"The Campanian–Paleocene Jaworzynka Formation, a part of the Magura Nappe succession in the Polish Outer Carpathians, is described in terms of its detailed litho- and biostratigraphy. The formation stretches along the marginal part of the Siary Unit, from the Jaworzynka stratotype area in the Silesian Beskid Mts up to the Mszana Dolna area in the Beskid Wyspowy Mts. Its equivalent in the Moravskoslezske Beskydy Mts of the Czech Republic is the Solaň Formation. In the stratotype area, the formation displays complex structure. We distinguish four lithological units, i.e. Biotite Sandstone and Shale (I), Shale (II), Mutne Sandstone Member (III) and Thin-bedded Turbidite (IV) and provide the first detailed biostratigraphy of particular units. The first unit forms the most prominent part of the formation. It was deposited in the Middle Campanian–earliest Maastrichtian within the upper part of Caudammina gigantea Zone up to the lower part of the Rzehakina inclusa Zone. The second unit occurs only locally and its age is limited to the Maastrichtian, to the Rzehakina inclusa Zone. The third unit is composed of thick-bedded sandstones that in some parts may form more than the half of the total thickness of the formation. It is Late Maastrichtian–Danian in age and is placed in the upper part of the Rzehakina inclusa Zone and the lower part of the Rzehakina fissistomata Zone. It is usually covered by a thin package of thin-bedded turbiditic sandstone and shales of Danian–Thanetian age with foraminifera of the Rzehakina fissistomata Zone.","PeriodicalId":7030,"journal":{"name":"Acta Geologica Polonica","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46815095","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}
Pub Date : 2023-06-27DOI: 10.24425/agp.2023.145617
Andrzej Kozłowski, Witold Matyszczak
: Kozłowski, A. and
: Kozłowski, A.和
{"title":"Native silver in the eastern part of the Karkonosze granitoid pluton, Lower Silesia, Poland","authors":"Andrzej Kozłowski, Witold Matyszczak","doi":"10.24425/agp.2023.145617","DOIUrl":"https://doi.org/10.24425/agp.2023.145617","url":null,"abstract":": Kozłowski, A. and","PeriodicalId":7030,"journal":{"name":"Acta Geologica Polonica","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48728973","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}
Pub Date : 2023-06-27DOI: 10.24425/agp.2022.143600
J. Dunlop, V. Dernov
: Dunlop, J.A. and Dernov, V.S. 2023. The first trigonotarbid arachnid from Ukraine. Acta Geologica Polonica , 73 (2), 181–187. Warszawa. The extinct arachnid order Trigonotarbida Petrunkevitch, 1949 is reported here for the first time from Ukraine. The material consists of an opisthosoma preserved in ventral view from the upper Carboniferous (lower Moscovian; Paralegoceras – Eowellerites ammonoid zone) of the Gorlivka locality in the Donets Basin, eastern Ukraine. Formal assignment to a family or genus is difficult, but the preserved ventral anatomy is consistent with a member of the families Aphantomartidae Petrunkevitch, 1945, Kreischeriidae Haase, 1890 or Eophrynidae Karsch, 1882. It is noteworthy for expanding the known distribution of trigonotarbids in Europe and is only the second Palaeozoic arachnid to be formally described from Ukraine; the other being the carapace of a whip scorpion (Thelyphonida Latreille, 1804) from Lomovatka in the Luhansk Region, also in the Donets Basin.
{"title":"The first trigonotarbid arachnid from Ukraine","authors":"J. Dunlop, V. Dernov","doi":"10.24425/agp.2022.143600","DOIUrl":"https://doi.org/10.24425/agp.2022.143600","url":null,"abstract":": Dunlop, J.A. and Dernov, V.S. 2023. The first trigonotarbid arachnid from Ukraine. Acta Geologica Polonica , 73 (2), 181–187. Warszawa. The extinct arachnid order Trigonotarbida Petrunkevitch, 1949 is reported here for the first time from Ukraine. The material consists of an opisthosoma preserved in ventral view from the upper Carboniferous (lower Moscovian; Paralegoceras – Eowellerites ammonoid zone) of the Gorlivka locality in the Donets Basin, eastern Ukraine. Formal assignment to a family or genus is difficult, but the preserved ventral anatomy is consistent with a member of the families Aphantomartidae Petrunkevitch, 1945, Kreischeriidae Haase, 1890 or Eophrynidae Karsch, 1882. It is noteworthy for expanding the known distribution of trigonotarbids in Europe and is only the second Palaeozoic arachnid to be formally described from Ukraine; the other being the carapace of a whip scorpion (Thelyphonida Latreille, 1804) from Lomovatka in the Luhansk Region, also in the Donets Basin.","PeriodicalId":7030,"journal":{"name":"Acta Geologica Polonica","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44920877","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}
Pub Date : 2023-06-27DOI: 10.24425/agp.2022.143599
S. Skompski, Anna Kozłowska, Wojciech Kozłowski, P. Łuczyński
: Skompski, S., Kozłowska, A., Kozłowski, W. and Łuczyński, P. 2023. Coexistence of algae and a graptolite-like problematicum: a case study from the late Silurian of Podolia (Ukraine). Acta Geologica Polonica , 73 (2), 115–133. Warszawa. This contribution presents the record of an abundant assemblage of well-preserved, thallophytic noncalcified algae and of an epibiotic form that has been recognised as a putative graptolite from the upper Silurian (Ludlow, Gorstian–Ludfordian) of Podolia (western part of Ukraine). The sediments represent a shallow peritidal zone of the shelf. A new genus and species, Voronocladus dryganti , belonging to the Dasycladales Pascher, 1931, is established. Most of the specimens representing the algal thallus are overgrown by problematical epibiotic graptolites, described as Podoliagraptus algaeoides gen. et sp. nov. This phenomenon is explained as an epi - phytic mode of life of the putative graptolite on algae, and is herein compared to recently known coexistences of algae with other organisms. The excellent state of preservation, and the abundance of studied Dasycladales algae and epibiotic problematics indicate that the investigated mudstone layer can be treated as a ‘Konservat Lagerstätte’ sensu Seilacher (1970).
{"title":"Coexistence of algae and a graptolite-like problematicum: a case study from the late Silurian of Podolia (Ukraine)","authors":"S. Skompski, Anna Kozłowska, Wojciech Kozłowski, P. Łuczyński","doi":"10.24425/agp.2022.143599","DOIUrl":"https://doi.org/10.24425/agp.2022.143599","url":null,"abstract":": Skompski, S., Kozłowska, A., Kozłowski, W. and Łuczyński, P. 2023. Coexistence of algae and a graptolite-like problematicum: a case study from the late Silurian of Podolia (Ukraine). Acta Geologica Polonica , 73 (2), 115–133. Warszawa. This contribution presents the record of an abundant assemblage of well-preserved, thallophytic noncalcified algae and of an epibiotic form that has been recognised as a putative graptolite from the upper Silurian (Ludlow, Gorstian–Ludfordian) of Podolia (western part of Ukraine). The sediments represent a shallow peritidal zone of the shelf. A new genus and species, Voronocladus dryganti , belonging to the Dasycladales Pascher, 1931, is established. Most of the specimens representing the algal thallus are overgrown by problematical epibiotic graptolites, described as Podoliagraptus algaeoides gen. et sp. nov. This phenomenon is explained as an epi - phytic mode of life of the putative graptolite on algae, and is herein compared to recently known coexistences of algae with other organisms. The excellent state of preservation, and the abundance of studied Dasycladales algae and epibiotic problematics indicate that the investigated mudstone layer can be treated as a ‘Konservat Lagerstätte’ sensu Seilacher (1970).","PeriodicalId":7030,"journal":{"name":"Acta Geologica Polonica","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43156914","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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