Sökning: "conodonts"

Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet conodonts.

  1. 1. Middle ordovician conodonts from the Atlantic faunal region and the evolution of key conodont genera

    Författare :Jianhua Zhang; Anita Löfgren; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Conodonts; Middle Ordovician; Biostratigraphy and lithofacies; Evolution; Atlantic Faunal Region; Earth sciences; Geovetenskap; allmän och historisk geologi; General and Historical Geology;

    Sammanfattning : This thesis consists of seven separate articles that are mainly concerned with Middle Ordovician conodonts. The studied conodont specimens were obtained from three Middle Ordovician sections in south China and four Middle Ordovician sections in Sweden. LÄS MER

  2. 2. Late Ordovician-Early Silurian facies development and stratigraphy of Jämtland, central Sweden

    Författare :Peter Dahlqvist; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; biostratigraphy; Sedimentology; Stratigrafi; Stratigraphy; Paleontologi; Palaeontology; Jämtland; provenance; brachiopods; conodonts; Hirnantian; Silurian; Ordovician; glaciation; eustasy; Sedimentologi; sedimentology;

    Sammanfattning : This thesis is based on studies of Lower Palaeozoic sedimentary successions within the central Scandinavian Caledonides. These deposits have been transported by considerable nappe displacement (several kilometres), and are today relatively isolated from the nearest coeval outcrops (Dalarna 250 km, Oslo Region 350 km). LÄS MER

  3. 3. Conodont biostratigraphy, taxonomy and palaeoecology in the Darriwilian (Middle Ordovician) of Baltoscandia - with focus on meteorite and extraterrestrial chromite-rich strata

    Författare :Johanna Mellgren; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Conodonts; biostratigraphy; taxonomy; palaeoecology; morphometrics; extraterrestrial chromite; meteorites; Darriwilian; Middle Ordovician; Baltoscandia;

    Sammanfattning : This thesis deals with conodont biostratigraphy and palaeoecology in the Darriwilian (Middle Ordovician) of Baltoscandia, with focus on limestone strata showing traces of the ~ 470 Ma L-chondrite parent body break-up. The evidence for this cosmic event includes abundant centimeter to decimeter-sized fossil meteorites and elevated levels of sediment-dispersed extraterrestrial L-type chromite found in a stratigraphical interval corresponding to the uppermost Lenodus antivariabilis, the L. LÄS MER

  4. 4. Conodont biostratigraphy and diversity in The Lower-Middle Ordovician of Eastern Baltoscandia (St. Petersburg region, Russia) and Kazakhstan

    Författare :Tatiana Tolmacheva; Richard Aldrigde; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Earth sciences; Geovetenskap; Earth sciences; Geovetenskap; Historical Geology and Paleontology; historisk geologi och paleontologi;

    Sammanfattning : Conodonts were first discovered and described by Christian Pander in 1856 from the St. Petersburg region. LÄS MER

  5. 5. Ordovician (Billingen and Volkhov stages) Brachiopod Faunas of the East Baltic

    Författare :Eva Egerquist; Lars Holmer; John S. Peel; Michael G. Bassett; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Earth sciences; Early Middle Ordovician; Billingen Regional Stage; Volkhov Regional Stage; Diversity; Brachiopoda; Conodonta; Ostracoda; Estonia; Russia; Geovetenskap; Earth sciences; Geovetenskap;

    Sammanfattning : Lower-Middle Ordovician (Arenig) successions in the East Baltic have been investigated for more than one hundred and fifty years. Nevertheless detailed sampling still yields new species and better knowledge of the environment in which these organisms lived. LÄS MER