Essays about: "acritarchs"
Showing result 1 - 5 of 8 essays containing the word acritarchs.
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1. Investigation of Thermal Maturity of Organic Matter at the Cambro Ordovician Transition in the Zagros Basin, Iran
University essay from Uppsala universitet/Institutionen för geovetenskaperAbstract : The thermal maturity of sediments from the upper Cambrian to lower Ordovician Mila and Ilbeyk formations in the Zagros Basin in southwestern Iran is evaluated in this thesis. A number of low-cost, fast, optical evaluation methods are utilised to assess their effectiveness for providing accurate, well constrained thermal maturity results. READ MORE
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2. Biodiversity of Organic-Walled Eukaryotic Microfossils from the Tonian Visingsö Group, Sweden
University essay from Uppsala universitet/Institutionen för geovetenskaperAbstract : The diversification of unicellular, auto- and heterotrophic protists and the appearance of multicellular microorganisms is recorded in numerous Tonian age successions worldwide, including the Visingsö Group in southern Sweden. The Tonian Period (1000-720 Ma) was a time of changes in the marine environments with increasing oxygenation and a high input of mineral nutrients from the weathering continental margins to shallow shelves, where marine life thrived. READ MORE
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3. The life cycle and developmental phases of Cambrian-Ordovician organic-walled microfossils from Kolguev Island, Arctic Russia.
University essay from Uppsala universitet/Institutionen för geovetenskaperAbstract : Light microscopy studies of collections of late Cambrian/Early Ordovician organic-walled microfossils, informally called acritarchs, provide the observations on phenotypic traits that are comparable to Modern microalgae and make possible recognition of various developmental stages in their complex life cycle. The exceptionally preserved Saharidia fragilis microfossils show the internal body within the vesicle and the formation of the fringe and pylome, the opening for releasing of the daughter cells from the phycoma-like cyst. READ MORE
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4. A palynological study across the Ordovician Kinnekulle bentonite, Sweden
University essay from Lunds universitet/Geologiska institutionenAbstract : A palynological analysis across the Ordovician (Sandbian) Kinnekulle bentonites in south Central Sweden has been performed. The sedimentary successions were recovered from the Borenshult -1 drillcore in the Motala area, south central Sweden. The lithology is dominated by mudstones and two thick bentonite beds. READ MORE
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5. Sequence stratigraphy, palynology and biostratigraphy across the Ordovician-Silurian boundary in the Röstånga-1 core, southern Sweden
University essay from Lunds universitet/Geologiska institutionenAbstract : A multiproxy study on sedimentary rocks spanning the Ordovician-Silurian boundary has been performed on material from the Röstånga-1 core, with the aims to improve the biostratigraphical and sedimentological framework and to interpret the depositional environment during this interval in Earth’s history. The sedimentary succession in the Röstånga-1 core is developed in the Scanian Lithofacies Belt and is considered an excellent upper Middle Ordovician-Lower Silurian reference section for southernmost Sweden. READ MORE
