Sökning: "biostratigraphy"

Visar resultat 1 - 5 av 31 avhandlingar innehållade ordet biostratigraphy.

1. 1. Late Quaternary Biostratigraphy and Paleoceanography of the central Arctic Ocean

   Författare :Daniela Hanslik; Martin Jakobsson; Marit-Solveig Seidenkrantz; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Arctic Ocean; Quaternary; biostratigraphy; foraminifera; paleoceanography; Other earth sciences; Övrig geovetenskap; Marine Geoscience; marin geovetenskap;

   Sammanfattning : The central Arctic Ocean is one of the least explored deep sea regions and long biostratigraphic sediment records are sparse. The main focus of this thesis is the Arctic Ocean foraminiferal record and its application to reconstruct paleoceanographic variations and summer sea ice cover changes between late Quaternary interglacial periods. LÄS MER

3. 2. The lower and middle Cambrian of Sweden: trilobites, biostratigraphy and intercontinental correlation

   Författare :Niklas Axheimer; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sedimentologi; Paleontologi; Palaeontology; fysisk geografi; Geologi; physical geography; Geology; Sweden; correlation; trilobites; biostratigraphy; Cambrian; Sedimentology;

   Sammanfattning : This thesis is based on studies of Cambrian successions in Sweden, with particular focus on the middle Cambrian biostratigraphy and its correlative relationship to the proposed global agnostoid zonation. The investigated material, mainly trilobites, was collected from both outcrops and drill cores from five provinces in Sweden: Skåne (Scania), Öland, Västergötland, Jämtland and Lapland. LÄS MER

4. 3. Middle and Upper Ordovician graptolites, trilobites, and biostratigraphy of Scania and Jämtland, Sweden

   Författare :Christian Pålsson; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; physical geography; Geology; Sweden; Jämtland; Scania Skåne ; Upper Ordovician; Middle Ordovician; palaeoecology; biostratigraphy; lithostratigraphy; Graptolites; trilobites; Geologi; fysisk geografi; Palaeontology; Paleontologi;

   Sammanfattning : Graptolites and some trilobites from Middle–Upper Ordovician siliciclastic and calcareous rocks in Scania (Skåne), southern Sweden, and Jämtland, central Sweden, are described and discussed. Their stratigraphic distribution is discussed on the basis of new and old collections from outcrops and drill cores. LÄS MER

5. 4. Biostratigraphy and Systematics of Cambrian Small Shelly Fossils from East Antarctica and South Australia

   Författare :Thomas M. Claybourn; Lars E. Holmer; Glenn A. Brock; Christian B. Skovsted; Graham Budd; David Harper; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cambrian; Biostratigraphy; Systematics; East Antarctica; Small Shelly Fossils;

   Sammanfattning : The remote lower Cambrian Byrd group of sedimentary rocks from East Antarctica has been studied intermittently since its discovery over a century ago. Previous insights into the trilobites and archaeocyaths indicated a close correlation to the sedimentary sequences of South Australia. LÄS MER

7. 5. 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; 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