Sökning: "Early Cretaceous"

Visar resultat 1 - 5 av 20 avhandlingar innehållade orden Early Cretaceous.

1. 1. Jurassic and Early Cretaceous selachians - focus on southern Scandinavia

   Författare :Jan Rees; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geology; Paleontologi; Palaeontology; Lissodus; palaeoecology; England; Denmark; Sweden; sharks; selachians; Jurassic; Early Cretaceous; physical geography; Geologi; fysisk geografi;

   Sammanfattning : The Jurassic and Early Cretaceous selachian faunas of Scania (Skåne), southern Sweden and the island of Bornholm (Denmark) have been investigated. Three Early Jurassic shark tooth assemblages have been recorded and investigated, one from Hettangian strata and the other two from Pliensbachian sediments. LÄS MER

3. 2. Cretaceous palynofloras from southern Scandinavia

   Författare :Vivi Vajda; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Paleobotanik; phylogeny; Palaeobotany; Cingutriletes scanicus sp. nov; Palynology; palynofacies; paleovegetation; transgression; Early Cretaceous; Cenomanian; Turonian; Bornholm; Denmark; Sweden; Scania; fylogeni; palynologi; Geology; physical geography; Geologi; fysisk geografi;

   Sammanfattning : A palynological investigation of Cretaceous sequences from Höllviken 2, Svedala 1 and Norrevång 1 wells of Scania, Southern Sweden, and from the Arnager Greensand-Arnager Limestone transition on the island of Bornholm, Denmark, was conducted. Well preserved palynofloras were found in strata consisting of shaly mudstones, glauconitic sandstones (greensand) and limestone. LÄS MER

4. 3. Jurassic and Early Cretaceous selachians - focus on southern Scandinavia

   Författare :Jan Rees; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Biologi;

   Sammanfattning : .... LÄS MER

5. 4. Origin and the evolution of diatoms through the integration of paleontology and phylogenetics

   Författare :Karolina Brylka; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diatoms; evolution; fossil record; Cretaceous; molecular evolution; Mesozoic; silicon transporter proteins; gene duplication;

   Sammanfattning : Diatoms, the prominent photosynthetic eucaryotes, have inhabited the world’s oceans for at least the past 120 Ma since their first appearance in the Lower Cretaceous. There are also records of older diatoms, from the Jurassic dating to ca. 172 Ma and ca. 165 Ma, however these are poorly documented. LÄS MER

7. 5. Geochemical and sedimentary signatures of Phanerozoic events

   Författare :Jane Wigforss-Lange; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; geokemi; Sedimentology; Petrology; mineralogy; geochemistry; Petrologi; mineralogi; Carbon and oxygen isotopes; Jurassic-Cretaceous boundary; K-T boundary; Late Silurian; Events; Trace elements; Sedimentologi;

   Sammanfattning : Geological and biological catastrophic events have occurred repeatedly in the Earth's history, leaving traces in the global stratigraphical record in the form of sedimentary features, geochemical anomalies and biotic turnovers. This thesis focuses on the sedimentological and geochemical signatures of several key events in the Phanerozoic stratigraphical record, and aims to interpret the different signals and the causal mechanisms behind each of these events. LÄS MER