Sökning: "biostratigraphy"

Visar resultat 26 - 30 av 31 avhandlingar innehållade ordet biostratigraphy.

1. 26. Cambro-Ordovician microorganisms: acritarchs and endoliths

   Författare :Martin Stockfors; Malgorzata Vidal-Moczydlowska; John S. Peel; Kenneth John Dorning; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Cambrian; Ordovician; acritarch; endolith; Kolguev Island; North Greenland; Stratigraphy; Geovetenskap; Earth sciences; Geovetenskap;

   Sammanfattning : Organic-walled microfossils are abundant and taxonomically diverse in Cambrian-Ordovician strata; some are important for biostratigraphy and for the correlation of geological successions. New assemblages of Cambrian-Ordovician acritarchs from Kolguev Island, Arctic Russia and Middle Cambrian ichnofossils of endoliths from Peary Land, North Greenland are studied. LÄS MER

3. 27. Evolution and taxonomy of Cambrian arthropods from Greenland and Sweden

   Författare :Martin Stein; John S. Peel; Dieter Waloszek; David J. Siveter; Reinhardt M. Kristensen; David L. Bruton; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cambrian; Arthropods; Trilobites; Evolution; Greenland; Sweden; Historical geology and palaeontology; Historisk geologi och paleontologi;

   Sammanfattning : Arthropods have a rich fossil record spanning the Phanerozoic. Biomineralized forms such as the extinct trilobites are particularly common and are proven index fossils for biostratigraphy. Forms with an unmineralized cuticle are more rare, preserved only in so called konservat lagerstätten. LÄS MER

4. 28. Eurasian Arctic Tectonics: Geology of Severnaya Zemlya (North Kara Terrane) and Relationships to the Timanide Margin of Baltica

   Författare :Henning Lorenz; David G. Gee; Robert Scott; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Arctic; Severnaya Zemlya; North Kara Terrane; Baltica; bedrock; geology; tectonics; Timanides; Caledonides; Geovetenskap; Earth sciences; Geovetenskap;

   Sammanfattning : The North Kara Terrane (NKT), with Severnaya Zemlya as its main outcrop area, constitutes the Palaeozoic and older rocks of the northern part of the Kara Shelf. Potential field data suggest a continuation into the eastern Barents Shelf. LÄS MER

5. 29. Biostratigraphic implications of Neogene diatom abundances in the Norwegian Sea, the North Atlantic and the western North Pacific

   Författare :Per Bodén; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis consists of three separate articles and are mainly concerned with the taxonomy of species from the genus Thalassiosira and quantitative diatom biostratigraphy in three oceanic regions of the northern hemisphere. The study material consists of Ocean Drilling Program (ODP) Holes 642B, 642C and 644A at about 67°N in the Norwegian Sea, Deep Sea Drilling Project (DSDP) Hole 552A at 56 N in the North Atlantic, and DSDP Site 578 at 34°N in the northwest Pacific. LÄS MER

7. 30. Urbanised Nature in the Past : Site formation and Environmental Developement in Two Swedish Towns, AD 1200-1800

   Författare :Jens Heimdahl; Ann-Marie Robertsson; Jane Sidell; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Urban stratigraphy; environmental reconstruction; site formation; geoarchaeology; dark earth; macrofossil analysis; Quaternary geology; Kvartärgeologi;

   Sammanfattning : In order to explore site formations and reconstruct environmental development in Medieval and Post-Medieval towns, urban occupational strata in Norrköping and Karlstad were studied according to biostratigraphy, sedimentology and pedology. New field procedures including continuous pilot sampling, parallel archaeological and geological stratigraphic interpretation, and on-site analysis of plant macrofossils were developed and applied at archaeological excavations in both towns. LÄS MER